REFR
{
RETE|ID 1 FBrf0144466	AU 1 Adolfsen et al.	YR 1 2001	TP 1 Abstract	TI 1 Characterization of the Drosophila synaptotagmin family.	REFM 1 Bellen, Taylor, 2001: 18		
ID|FBrf0144466
TP|abstract
|Drosophila meeting abstract
MABST|A mechanistic understanding of how synaptic calcium signals are transduced
| into membrane fusion and neurotransmitter release is largely unknown.
| Biochemical and genetic studies on synaptotagmin I are consistent with the
| idea that synaptotagmin I is a major calcium sensor at synapses, although
| it likely plays multiple roles in vesicle cycling. Currently, 12
| synaptotagmin isoforms have been isolated in mammals, and six to eight
| homologues have been found in Drosophila and C. elegans. Outside of
| synaptotagmin I the function of the remaining synaptotagmins is unknown. We
| are interested in characterizing the localization, biochemistry and
| function of the Drosophila synaptotagmin family. Among the Drosophila C2
| family, eight proteins are most homologous to synaptotagmins. These include
| homologs of mammalian isoforms I, IV, VII, IX, V/ X, Srg-1, and two
| additional synaptotagmin-like proteins. Of these, only the synaptotagmin IX
| homolog lacks the a transmembrane domain. In addition, Drosophila contains
| a number of synaptotagmin-related proteins including one tricalbin homolog,
| one granuphilin homolog and one otoferlin homolog. Other C2-domain
| containing proteins include one Rabphilin homolog, one RIM homolog, three
| proteins with some homology to Munc-13, and four additional novel
| C2-containing proteins. We have generated antisera against the immediate
| synaptotagmin family and have initiated studies to determine the cellular
| and subcellular distribution of each isoform. We have also begun a
| biochemical analysis of the family to determine their calcium-dependent
| properties and protein-protein interactions. We will present our findings
| on the localization and biochemical properties of the Drosophila
| synaptotagmin family that will facilitate our subsequent genetic analysis
| to determine the function of the neuronal expressed isoforms.
AU|Adolfsen
|B.
AU|Mikula
|M.
AU|Littleton
|J.T.
YR|2001
TI|Characterization of the Drosophila synaptotagmin family.
JR|Bellen, Taylor, 2001
PG|18
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144467	AU 1 Almeida et al.	YR 1 2001	TP 1 Abstract	TI 1 Investigating the role of Notch and grainyhead in the post embryonic neuroblasts.	REFM 1 Bellen, Taylor, 2001: 180		
ID|FBrf0144467
TP|abstract
|Drosophila meeting abstract
MABST|Neuroblasts are the precursors, which give rise to the differentiated cells
| of the nervous system. In Drosophila, after the first stage of neurogenesis
| is complete in the late embryo, all but two of the neuroblasts (NBs) cease
| dividing. Many of the NBs then become dormant, whilst a few disappear,
| probably undergoing programmed cell death. The dormant NBs are reactivated
| in late second instar. They then proliferate producing clusters of progeny
| that contribute to the adult nervous system at metamorphosis. The larval
| postembryonic neuroblasts (pNBs) therefore have characteristics of neural
| stem cells since they have the ability to self-renew and to generate
| progeny that will contribute to the adult nervous system. Our interest in
| the pNBs has come from two directions. First we know that the Notch pathway
| is active in the pNB lineages, but we cannot easily reconcile this activity
| with known functions of Notch at other stages of neurogenesis. Second, we
| have been studying a gene, grainyhead which is expressed in the pNBs. We
| are now investigating the role of both genes, taking advantage of a pNB
| enhancer from grainyhead that allows us to manipulate gene expression in
| these cells. Our preliminary results from these analyses will be presented.
AU|Almeida
|M.
AU|Harrison
|E.
AU|Bray
|S.
YR|2001
TI|Investigating the role of Notch and grainyhead in the post embryonic neuroblasts.
JR|Bellen, Taylor, 2001
PG|180
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144468	AU 1 Arruda and Dolph	YR 1 2001	TP 1 Abstract	TI 1 An allele of pawn that disrupts phototransduction in Drosophila.	REFM 1 Bellen, Taylor, 2001: 119		
ID|FBrf0144468
TP|abstract
|Drosophila meeting abstract
MABST|We have isolated a novel mutation with dramatic effects on
| phototransduction. Mutant flies exhibit a novel electrophysiological
| response to light with high-frequency oscillations during photoreceptor
| cell depolarization. The allele also exhibits a rapid light-dependent
| retinal degeneration that appears unlike any that has been previously
| documented where microvilli are selectively lost from the distal tips of
| the rhabdomeres. In addition, there are several morphological traits
| associated with this allele, including, embryonic lethality, truncated
| bristles, and black melanic deposits on the eyes of mutant flies.
| Interestingly, mutations in the pawn gene share the lethality, bristle, and
| eye phenotypes however, these flies have neither the ERG nor the retinal
| degeneration phenotypes. Genetic data has demonstrated that our mutation is
| a new allele of pawn (pawn 14S7 ). Genetic and PCR analysis allowed us to
| map the molecular lesion to be a deletion in the CG11101 ORF resulting in a
| premature stop codon. In addition, three different pawn alleles were
| determined to have point mutations within this same coding region. CG11101
| is a single -pass transmembrane protein with a large extracellular domain
| and small cytoplasmic tail. Proteins with this architecture are classified
| as cell adhesion molecules. Data will be presented which suggests that the
| retinal degeneration and oscillating electroretinogram phenotypes
| characteristic of pawn 14S7 are due to the misexpression of the truncated
| Pawn product disrupting a vital process involved in phototransduction.
AU|Arruda
|S.E.
AU|Dolph
|P.J.
YR|2001
TI|An allele of pawn that disrupts phototransduction in Drosophila.
JR|Bellen, Taylor, 2001
PG|119
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144469	AU 1 Ghezzi et al.	YR 1 2001	TP 1 Abstract	TI 1 Transcriptional modulation of the Drosophila slowpoke gene after acute exposure to solvent anesthetics.	REFM 1 Bellen, Taylor, 2001: 19		
ID|FBrf0144469
TP|abstract
|Drosophila meeting abstract
MABST|Electrically excitable cells depend on the activity of ion channels to
| transmit information by means of electrical impulses. To efficiently convey
| information, the ion channel protein density must be tailored to the
| demands of the existing environment. An increase in channel density can
| have a strong impact on the cellular electrical properties. We have
| observed that exposure of the fruit fly Drosophila melanogaster to benzyl
| alcohol, an anesthetic that induces a hyperexcitable behavior, causes an
| increase in the mRNA abundance of the Ca2+ activated K+ channel, slowpoke
| (slo). Message abundance was measured by Ribonuclease Protection Assay.
| However, to determine whether the increase was the result of increased
| message stability or an increase in slo transcription we used a transgenic
| line that contains the slo neuronal promoter upstream of the
| b-galactosidase reporter gene. b-galactosidase levels were measured
| following acute treatment with benzyl alcohol. The observed increase in of
| b-galactosidase's specific activity is an indicator that the increase in
| slo mRNA is partially a result of a transcriptional response.
AU|Ghezzi
|A.
AU|Al-Hasan
|Y.M.
AU|Larios
|L.E.
AU|Atkinson
|N.S.
YR|2001
TI|Transcriptional modulation of the Drosophila slowpoke gene after acute exposure to solvent anesthetics.
JR|Bellen, Taylor, 2001
PG|19
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144470	AU 1 Awasaki and Ito	YR 1 2001	TP 1 Abstract	TI 1 Development of the clonal unit, lineage-related neural circuit module.	REFM 1 Bellen, Taylor, 2001: 146		
ID|FBrf0144470
TP|abstract
|Drosophila meeting abstract
MABST|The central brain of Drosophila melanogaster is produced by an average of 85
| stem cells (neuroblasts) per hemisphere. In order to assess the role of
| cell lineage in the neural circuit formation, we visualized the innervation
| patterns of the progeny of single neuroblasts in the adult brain using the
| FRT-GAL4 system. In the majority of clones identified so far, cell bodies
| form a tightly packed cluster. Their neurites fasciculate to form a single
| bundle and innervate a limited number of neuropile regions in a stereotypic
| manner. These suggest that, in many cases, the progeny of a single
| neuroblast form a lineage-dependent circuit module, which we named a
| "clonal unit". In the developing larval brain, clustering of clonal cell
| bodies and fasciculation of neurites are already apparent. To understand
| the mechanisms underlying this clonal clustering and fasciculation, we
| first focused on the role of neural-specific homophilic cell adhesion
| molecules in the cell body layer (cortex) of the developing larval brain.
| DN-cadherin and Neuroglian are distributed uniformly along the border
| between all the neurons. FasciclinII (FasII), on the other hand, localizes
| in several clusters of neurons, each of which looks like clonally related.
| Double labeling of FRT-GAL4 clones and FasII-expressing cells revealed that
| FasII clusters indeed correspond to clones. The distribution of FasII is
| limited to the cell border inside the clones. Cell surface flanking the
| neighboring clones is free of FasII. Such localization might infer that
| FasII would mediate cell-cell adhesion within clonal cluster. fasII mutant
| clones induced by the MARCM system, however, showed no remarkable defect on
| the formation of clonal cell clustering. Pan-neuronal ectopic expression of
| fasII, induced by the elav promoter, caused little effect, either. The
| ectopically expressed FasII, on the other hand, showed the same
| characteristic localization pattern: it concentrates along the intraclonal
| cell borders but not along the interclonal cell borders. Why doesn't
| ectopic FasII exist at the interclonal cell borders? One possible
| explanation is that there might be physical boundary that prevents direct
| contact of neurons between different clones. We thus examined the
| arrangement of glial cells in the larval brain. Double labeling of glial
| cells and FasII -expressing clones showed that a type of glia -cell body
| glial cells -send extensive processes between neurons. In the outer area of
| the cell body layer, which is near the brain surface and houses neuroblasts
| and newly generated cells, glial processes wrap only the outer surface of
| the clonal clusters. Processes are not observed within the cluster. Glial
| cells thus physically separate the clonal border in this area. Deeper in
| the cell body layer, which consists of old cells, thin glial processes
| penetrate the boundary between essentially all the neurons.
AU|Awasaki
|T.
AU|Ito
|K.
YR|2001
TI|Development of the clonal unit, lineage-related neural circuit module.
JR|Bellen, Taylor, 2001
PG|146
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144471	AU 1 Babcock and Pallanck	YR 1 2001	TP 1 Abstract	TI 1 A screen for synaptic transmission mutants in Drosophila.	REFM 1 Bellen, Taylor, 2001: 20		
ID|FBrf0144471
TP|abstract
|Drosophila meeting abstract
MABST|The fly compound eye is a powerful system for identifying and characterizing
| genes involved in signal transduction, synaptic transmission and
| neurodegeneration. Our lab is using the EGUF/ hid system (Stowers &
| Schwarz, 1999, Genetics 152, 1631) to conduct a screen for synaptic vesicle
| trafficking components that function in the photoreceptor presynaptic
| terminal. When used in a screening context, this system generates F1 mosaic
| offspring bearing photoreceptor cells that are homozygous for a particular
| mutagenized chromosome arm. We have used this system to screen 7500
| mutagenized chromosomes for defects conferring non-phototactic phenotypes.
| Characterization of 50 mutants recovered from this screen using
| electroretinogram recordings revealed five mutants with normal
| photoreceptor depolarization, but defective synaptic transmission. These
| mutants are currently being subjected to deficiency mapping, and further
| electrophysiological analysis at the neuromuscular junction. Results from
| these experiments will be presented.
AU|Babcock
|M.
AU|Pallanck
|L.
YR|2001
TI|A screen for synaptic transmission mutants in Drosophila.
JR|Bellen, Taylor, 2001
PG|20
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144472	AU 1 Baines et al.	YR 1 2001	TP 1 Abstract	TI 1 Fasciclin II regulates synaptic connetivity in the embryonic CNS.	REFM 1 Bellen, Taylor, 2001: 92		
ID|FBrf0144472
TP|abstract
|Drosophila meeting abstract
MABST|The mechanisms that underlie the formation of synaptic connections in the
| CNS are not well understood. It is conceivable, however, that molecules
| required for synaptic development at the more accessible peripheral
| neuromuscular junction (NMJ) may similarly contribute to synaptogenesis in
| the CNS. To test this, we have investigated the involvement of Fasciclin II
| (FasII), a key molecule involved in axonal guidance, target selection and
| synaptic plasticity at the Drosophila NMJ, in the development of identified
| synapses between cholinergic interneurons and glutaminergic motorneurons in
| the embryonic CNS. We will show that although the initial formation of
| synaptic connections between these neurons is independent of FasII, it is
| required for the subsequent elaboration of these connections during
| postembryonic development. To this extent therefore, the involvement of
| FasII in central synaptogenesis parallels that at the NMJ. Although FasII
| is not essential for the initial formation of central synapses in the
| embryo, asymmetric alterations in the level of its expression, induced via
| targeted transgene expression in either the pre or postsynaptic neuron( s),
| are sufficient to disrupt the formation of a normal pattern of embryonic
| synaptic connectivity. This effect is isoform specific, being observed only
| with expression of a transmembrane (TM) isoform, but not a glycosyl
| phosphatidyl inositol (GPI)-linked isoform of FasII. We link this
| specificity in effect to our observation that the relative abundance of
| mRNA encoding TM, but not GPI-linked, isoforms of FasII is influenced by
| blocking evoked neurotransmitter release in all neurons of the embryonic
| CNS. This latter finding implies that synaptic activity, acting through
| altered levels of FasII expression, may contribute to the establishment of
| a proper pattern of central synaptic connections during embryogenesis.
AU|Baines
|R.A.
AU|Seugnet
|L.
AU|Thompson
|A.
AU|Bate
|M.
YR|2001
TI|Fasciclin II regulates synaptic connetivity in the embryonic CNS.
JR|Bellen, Taylor, 2001
PG|92
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144473	AU 1 Yu et al.	YR 1 2001	TP 1 Abstract	TI 1 Regulation of effector and initiator caspases in the development of the Drosophila eye.	REFM 1 Bellen, Taylor, 2001: 3		
ID|FBrf0144473
TP|abstract
|Drosophila meeting abstract
MABST|Regulated cell death and survival play important roles in neural
| development. Seven apparent caspases are presumed to be regulated by
| extracellular signals to determine the final structure of the nervous
| system. We found that an antibody raised against a peptide from human
| caspase 3 crossreacts specifically with dying Drosophila cells, and used
| this reagent to investigate how extracellular signals control spatial
| patterning of cell death during eye development. The antibody labeled
| activated effector caspases DCP-1 and Drice. We show that the initiator
| caspase DRONC and the proapoptotic gene head involution defective (hid)
| were are important for DCP1/ Drice activation in vivo. We have evidence
| that DRONC may also play direct roles in addition to activating downstream
| effector caspases. EGFR, Notch, and intact primary pigment and cone cells
| have each been implicated in survival or death signals in the eye.
| Epistasis experiments ordered these three signals into a single pathway
| that affects caspase activity through Inhibitor-of-Apoptosis proteins
| (IAPs). None of these extracellular signals appeared to act by promoting
| caspase activation directly. Taken together, these findings indicate that
| spatial regulation of cell death and survival is integrated through a
| single pathway in eye development.
AU|Yu
|S.Y.
AU|Yoo
|S.J.
AU|Yang
|L.
AU|Zapata
|C.
AU|Srinivasan
|A.
AU|Hay
|B.A.
AU|Baker
|N.E.
YR|2001
TI|Regulation of effector and initiator caspases in the development of the Drosophila eye.
JR|Bellen, Taylor, 2001
PG|3
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144474	AU 1 Baker et al.	YR 1 2001	TP 1 Abstract	TI 1 Ciliogenesis mutations affect sensory neuron function.	REFM 1 Bellen, Taylor, 2001: 120		
ID|FBrf0144474
TP|abstract
|Drosophila meeting abstract
MABST|Dendritic outer segments, the probable sites of transduction in external
| sense organs and chordotonal organs, are modified cilia. While some
| mutations affecting mechanosensory response have identified components of
| the transduction machinery, others disrupt the development or structure of
| these modified cilia. Previously, it was shown that some mutations with
| defects in axoneme structure affected chordotonal cilia, but not the highly
| modified cilia in es organs (Eberl et al, 2000). Here we describe genes
| that act in all ciliated sensory neurons. One class, which appears to be
| required for the generation of a functional basal body from its antecedent
| centriole, includes the unc and nompJ mutations. In unc mutants the cilia
| of chordotonal organs and the flagella of spermatids are often broken or
| splayed. The basal bodies of these cells are disrupted. These flies also do
| not produce motile sperm, and show defects in nuclear reshaping and
| individualization. A functional GFP tagged version of the novel protein
| localizes to centrioles and centriole adjuncts during spermatogenesis and
| to basal bodies during sense organ development. We are working to identify
| functional domains by dissecting the 1386 AA protein. One construct,
| consisting of the amino-terminal 977 AA, localizes to centrioles during
| spermatogenesis, but does not rescue. A slightly shorter construct of 663
| AA does not localize or rescue. Surprisingly a UAS-construct containing the
| carboxy-terminal 723 amino acids can rescue the mutant phenotype. Although
| UNC-GFP is localized to centrioles at the earliest stages of
| spermatogenesis, meiosis is completed normally in unc mutants. By contrast,
| nompJ mutants show meiotic defects, indicating an earlier requirement for
| this gene product. Spermatids and spermatocytes in these flies also
| mislocalize UNC-GFP and gamma-tubulin. We are currently mapping nompJ and
| further defining the mutant phenotype. Members of the second class,
| typified by nompB, have defects in both chordotonal and bristle sensory
| cells. nompB flies do not produce the elongated ciliary outer-segments
| typical of chordotonal sensory neurons, and show a gap between the neuron
| and cuticular dome in campaniform sensilla. The probable nompB gene encodes
| the Drosophila homolog of IFT88/ OSM-5/ Polaris, a conserved protein
| expressed in ciliated cells from algae to mammals. Homologs are part of a
| protein complex that mediates transport to and from the tip of growing
| cilia and flagella. Interestingly, although the protein is required to
| construct a variety of cilia in these taxa, nompB mutations do not prevent
| the production of motile sperm in Drosophila: either fly sperm do not
| require IFT, or it is required after spermatogenesis. We are currently
| asking if nompB is needed for sperm function.
AU|Baker
|J.D.
AU|Han
|Y.G.
AU|Kernan
|M.
YR|2001
TI|Ciliogenesis mutations affect sensory neuron function.
JR|Bellen, Taylor, 2001
PG|120
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144475	AU 1 Hatzidakis et al.	YR 1 2001	TP 1 Abstract	TI 1 Characterization of fruitless-expressing cells and their role in male sexual behavior.	REFM 1 Bellen, Taylor, 2001: 105		
ID|FBrf0144475
TP|abstract
|Drosophila meeting abstract
MABST|The fruitless (fru) gene heads a branch of the sex determination hierarchy
| that builds the potential for male sexual behavior into Drosophila
| melanogaster. Transcripts from the 4 promoters of the fruitless gene encode
| BTB zinc-finger transcription factors. The transcripts from the most
| upstream fru promoter (P1) are sex-specifically spliced and it is the
| P1-derived products that are responsible for fru's role in male sexual
| behavior. Male flies null for the P1 encoded proteins do not court, whereas
| P1 hypomorphs show defects throughout the courtship sequence. The absence
| of P1-derived products in females has no apparent phenotype. The P1-derived
| products of fru are expressed in about 2% of the cells of the central
| nervous system (about 1700 cells). Most of these neurons are found in about
| 20 clusters of fruitless-expressing cells; the remainder appear as isolated
| cells. We want to understand the roles of the different clusters of
| fru-expressing cells in the different stages of male sexual behavior. To
| achieve this goal, we are currently isolating the enhancers of fruitless,
| expecting that different enhancers can be identified that drive expression
| in different subsets of fru-expressing cells. We have tested over 25
| fragments from across the 140 KB fru transcriptional unit for enhancer
| activity with the GAL4-UAS system. We are determining whether these genomic
| fragments can act as enhancers by their ability to drive the expression of
| UAS-GFP in subsets of the cells in which products of the P1 fru promoter
| are normally expressed. The characterization of one enhancer which governs
| the expression of fru in the optic lobes will be presented. We are studying
| the roles that these, and other fru-expressing cells have in male sexual
| behavior by using the GAL4-UAS system to sexually transform and to cause
| the apoptosis of subsets of these cells.
AU|Hatzidakis
|J.
AU|Reynaud
|E.
AU|Baker
|B.
YR|2001
TI|Characterization of fruitless-expressing cells and their role in male sexual behavior.
JR|Bellen, Taylor, 2001
PG|105
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144476	AU 1 Banerjee and Hasan	YR 1 2001	TP 1 Abstract	TI 1 A study of intracellular signaling underlying axon guidance.	REFM 1 Bellen, Taylor, 2001: 204		
ID|FBrf0144476
TP|abstract
|Drosophila meeting abstract
MABST|Genetic analysis in Drosophila has lead to the discovery of many genes
| involved in wiring of the embryonic central nervous system. Several studies
| have provided a detailed understanding of how axons are guided with respect
| to the midline (reviewed by Tear G., 1999). Some neurons cross the midline
| once and project contralaterally, while others always project
| ipsilaterally, away or along the midline. It is becoming increasingly
| evident that a balanced output, generated by preferential expression of
| cell surface receptors and selective activation of intracellular signaling
| pathways guide an axon towards the midline or away from it. In an effort to
| link known extracellular pathways to specific intracellular signaling
| molecules, we have studied the role of dgq in axon guidance. dgq codes for
| the a subunit of the Gq class of heterotrimeric G proteins. Overexpression
| of the activated form of Gqa can reroute FasII positive axons cross the
| midline ( Ratnaparkhi and Hasan., 2001). Subsequent analysis suggested that
| Gqa is involved in modulating the repulsive behavior of a neuron, possibly
| in response to attractive cues. It has recently been shown that Abl Kinase
| regulates Robo mediated repulsive signaling (Bashaw GJ et al., 2000). One
| likely but speculative, hypothesis is that Gqa modulates repulsive
| signaling through activation of one or more tyrosine kinases. We are
| presently studying a group of tyrosine kinases as putative interactors of
| Gqa. Results of these studies will be discussed. References: Bashaw GJ et
| al., Cell. 2000 Jun 23; 101( 7): 703-15 Ratnaparkhi A and Hasan G. 2001(
| submitted). Tear G. Trends Genet. 1999 Mar; 15( 3): 113-8. Review
AU|Banerjee
|S.
AU|Hasan
|G.
YR|2001
TI|A study of intracellular signaling underlying axon guidance.
JR|Bellen, Taylor, 2001
PG|204
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144477	AU 1 Barolo et al.	YR 1 2001	TP 1 Abstract	TI 1 Hairless recruits the co-repressors CtBP and Groucho to the Notch pathway activator suppressor of hairless during PNS development.	REFM 1 Bellen, Taylor, 2001: 1		
ID|FBrf0144477
TP|abstract
|Drosophila meeting abstract
MABST|Suppressor of Hairless [Su( H)] is a DNA-binding transcription factor,
| conserved from flies to humans, which interacts with the activated Notch
| receptor to activate target genes. Su( H) is a transcriptional activator in
| the presence of Notch signaling, but can act as a repressor in the absence
| of signaling. We have previously shown that this repressor activity is
| essential for proper cell fate specification in the mechanosensory bristle
| 1 . Hairless (H), a novel protein, binds to Su( H) and has been pr oposed
| to inhibit Notch signaling by inhibiting DNA binding by Su( H) 2 . We will
| present evidence for an alternative hypothesis: that H antagonizes Notch
| signaling by acting as an adaptor between Su( H) and the co-repressors
| C-terminal Binding Protein (CtBP) and Groucho, thereby mediating direct
| repression of Notch target genes. We find that mutations in both dCtBP and
| groucho (gro) enhance the effects of loss of H function and of Su( H)
| de-repression during mechanosensory bristle development. This role for gro
| is surprising, since it has not previously been found to antagonize Notch
| signaling--in fact, gro is traditionally classified as a neurogenic gene.
| We will also show that the H protein contains conserved motifs that
| resemble CtBP and Gro interaction domains, and will present evidence that H
| directly interacts with both co-repressors in vitro. Our proposed "adaptor"
| model for H function conflicts with previous work 2 which indicated that an
| excess of H can block DNA-binding by Su( H) in vitro. We will present
| evidence that at lower H concentrations, Su( H) can bind simultaneously to
| both H and DNA in vitro. We will also describe in vivo misexpression
| experiments in which H-VP16 fusions act oppositely to wild -type H, a
| result consistent with a co-repressor/ adaptor model for H but not easily
| reconciled with a DNA-binding inhibition model. Taken together, these
| findings suggest an unusual mechanism for Su( H) -mediated repression of
| Notch target genes during PNS development. 1 Barolo, S., et al. (2000).
| Cell 103: 957-69. 2 Brou, C., et al. (1994). Genes Dev. 8: 2491-503.
AU|Barolo
|S.
AU|Stone
|T.
AU|Medders
|K.
AU|Posakony
|J.W.
YR|2001
TI|Hairless recruits the co-repressors CtBP and Groucho to the Notch pathway activator suppressor of hairless during PNS development.
JR|Bellen, Taylor, 2001
PG|1
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144478	AU 1 Barros et al.	YR 1 2001	TP 1 Abstract	TI 1 Myosins and asymmetic neuroblast division.	REFM 1 Bellen, Taylor, 2001: 147		
ID|FBrf0144478
TP|abstract
|Drosophila meeting abstract
MABST|During the neuroblast cell cycle, differential subcellular targeting of
| protein complexes results in the asymmetric segregation of cell fate
| determinants, such as Prospero. We are investigating the mechanisms that
| underlie the dynamic localisation of determinants in dividing neuroblasts.
| The actin cytoskeleton appears to play a fundamental role in establishing
| neuroblast asymmetry, as disruption of actin filaments leads to
| mislocalisation of Prospero. Treatment of neuroblasts with general myosin
| inhibitors, such as BDM, suggest that actin-based motor proteins may also
| be involved in asymmetric cell division. Furthermore the tumour-suppressor
| protein, Lethal giant larvae, which binds to non-muscle myosin II, was
| shown recently to play a role in asymmetric segregation. We are studying
| the role of different myosins in asymmetric cell division. We have followed
| the dynamic distribution of myosin II in living embryos and find that it is
| asymmetrically localised in neuroblasts. By blocking myosin II activity, we
| have shown that myosin II is essential for the asymmetric localisation of
| Prospero, Staufen and Numb. We are using similar approaches to investigate
| the role of unconventional myosins in the establishment of neuroblast asymmetry.
AU|Barros
|C.
AU|Phelps
|C.B.
AU|Brand
|A.H.
YR|2001
TI|Myosins and asymmetic neuroblast division.
JR|Bellen, Taylor, 2001
PG|147
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144479	AU 1 Bashaw et al.	YR 1 2001	TP 1 Abstract	TI 1 A novel Dbl family Rho GEF promotes axon attraction to the CNS midline and overcomes Robo repulsion.	REFM 1 Bellen, Taylor, 2001: 205		
ID|FBrf0144479
TP|abstract
|Drosophila meeting abstract
MABST|The key role of the Rho family GTPases -Rac, Rho and CDC42 -in regulating
| the actin cytoskeleton is well established. Increasing evidence suggests
| that the Rho GTPases and their upstream positive regulators-guanine
| nucleotide exchange factors (GEFs)-also play important roles in the control
| of growth cone guidance in the developing nervous system. Here we present
| the identification and molecular characterization of a novel Dbl family Rho
| GEF, GEF64C, that promotes axon attraction to the CNS midline in the
| embryonic Drosophila nervous system. GEF64C was identified in a gain of
| function interaction screen for enhancers of the Robo-DCC chimeric receptor
| phenotype. In sensitized genetic backgrounds, loss of GEF64C function
| causes a phenotype where too few axons cross the midline. In contrast,
| ectopic expression of GEF64C throughout the nervous system results in a
| phenotype in which far too many axons cross the midline, a phenotype
| reminiscent of loss of function mutations in the Roundabout (Robo)
| repulsive guidance receptor. Genetic analysis indicates that GEF64C
| over-expression can in fact overcome Robo repulsion. Surprisingly, evidence
| from genetic, biochemical and cell culture experiments suggests that the
| promotion of axon attraction by GEF64C is dependent on the activation of
| Rho, but not Rac or Cdc42.
AU|Bashaw
|G.J.
AU|Hu
|H.
AU|Nobes
|K.
AU|Goodman
|C.S.
YR|2001
TI|A novel Dbl family Rho GEF promotes axon attraction to the CNS midline and overcomes Robo repulsion.
JR|Bellen, Taylor, 2001
PG|205
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144480	AU 1 Armstrong et al.	YR 1 2001	TP 1 Abstract	TI 1 Identification of genes involved in gravitaxic responses in Drosophila.	REFM 1 Bellen, Taylor, 2001: 171		
ID|FBrf0144480
TP|abstract
|Drosophila meeting abstract
MABST|Gravity is an all-pervasive force on earth and generation of effective
| behavior by all higher organisms is predicated on perception of gravity. In
| Drosophila, the sense organs, processing centers and molecular pathways
| involved in receiving and responding to gravitational stimuli are unknown.
| We have used a gravitaxic maze testing paradigm to identify Drosophila
| mutants with aberrant gravitaxic responses. These mazes require flies to
| make up/ down choices at eight points and thus to exit at nine possible
| positions. The selection is therefore for mutant lines with maze exit
| profiles that are significantly different from those of appropriate control
| populations. In total we have screened approximately 1000 lines from two
| mutant collections: i) viable EMS mutants from the Zuker collection (C.
| Zuker, UC. San Diego) and ii) P {GAL4} insert-derived mutants generated by
| Armstrong and Kaiser (Glasgow University). A subset of 350 lines from the P
| {GAL4} collection that show expression in the adult CNS were used for our
| studies. Over 50 mutant lines with aberrant gravitaxic behavior have been
| isolated from the two collections. Most of these lines are normal for other
| complex behavior such as flight and courtship. The transposon insertion
| point for all 25 of the P {GAL4} lines producing aberrant gravitaxis has
| been established. In several lines, the affected gene has proved to be a
| gene with a previously established role in neural signaling or modeling. At
| least seven insertions appear to affect novel genes however. One of these
| insertions, which produces strong negative gravitaxis, is located in the
| ADH genomic region. Previous population genetics work in Hirsch's lab led
| to isolation of positive and negative gravitaxic populations and identified
| the ADH region as containing a locus affecting gravitaxic behavior (J Comp
| Physiol 110 p252, 1996). We have established that Hirsch's strongly
| negative gravitaxic population (" high line") carries a single amino acid
| change in the gene affected by our P {GAL4} insertion. This alteration is
| not present in three control strains examined, nor in the "low line"
| generated by Hirsch. In honor of the 40th anniversary of the first manned
| space flight by Yuri Gagarin, we have named the affected gene yuri. In
| adult heads, GAL4 expression from the yuri insert is found exclusively in
| the antennae and a small region of the CNS. Further characterization of
| yuri and other genes from our screen will be presented.
AU|Armstrong
|J.D.
AU|Texada
|M.J.
AU|Beckingham
|K.M.
YR|2001
TI|Identification of genes involved in gravitaxic responses in Drosophila.
JR|Bellen, Taylor, 2001
PG|171
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144481	AU 1 Berke and Wu	YR 1 2001	TP 1 Abstract	TI 1 Regional calcium regulation within cultured Drosophila neurons: Effects of altered cAMP metabolism by the learning mutations dunce and rutabaga.	REFM 1 Bellen, Taylor, 2001: 21		
ID|FBrf0144481
TP|abstract
|Drosophila meeting abstract
MABST|The dunce (dnc) and rutabaga (rut) mutations of Drosophila affect a
| cAMP-dependent phosphodiesterase and a Ca 2+ /CaM-regulated adenylyl
| cyclase, respectively. These mutations cause deficiencies in several
| learning paradigms and alter synaptic transmission, growth cone motility,
| and action potential generation. The cellular phenotypes are either Ca 2+
| -dependent (neurotransmission and motility) or mediate a Ca 2+ rise (action
| potential generation). However, inter-relations among these defects have
| not been addressed. We have established conditions for fura-2 imaging of Ca
| 2+ dynamics in the 'giant' neuron culture system of Drosophila. Using high
| K + depolarization of isolated neurons, we observed a larger, faster, and
| more dynamic response from the growth cone than cell body. This Ca 2+
| increase depended on an influx through Ca 2+ channels and was suppressed by
| the Na + channel blocker TTX. Altered cAMP metabolism by the dnc and rut
| mutations reduced response amplitude in the growth cone, while prolonging
| the response within the soma. The enhanced spatial resolution of these
| larger cells allowed us to analyze Ca 2+ regulation within distinct domains
| of the growth cone. We found that wild-type growth cones with motile
| filopodia exhibited a larger response to high K + -depolarization in the
| periphery than central domain. This distinction was disrupted by the rut
| mutation. Furthermore, both dnc and rut suppressed the facilitation by a
| prior conditioning depolarization (a decrease in response amplitude and
| waveform complexity). This may be related to previously described defects
| in the short-term plasticity of neurotransmission using a twin-pulse
| paradigm at the larval neuromuscular junction. The spatial resolution
| offered by optical imaging of cultured neurons complements
| electrophysiological studies in Drosophila. The two approaches in
| combination will greatly enhance the neurogenetic study of Ca 2+ -dependent
| processes in neuronal development and physiology.
AU|Berke
|B.
AU|Wu
|C.F.
YR|2001
TI|Regional calcium regulation within cultured Drosophila neurons: Effects of altered cAMP metabolism by the learning mutations dunce and rutabaga.
JR|Bellen, Taylor, 2001
PG|21
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144482	AU 1 Bier and Reiter	YR 1 2001	TP 1 Abstract	TI 1 How best to use Drosophila as a tool for analyzing human diseases.	REFM 1 Bellen, Taylor, 2001: 170		
ID|FBrf0144482
TP|abstract
|Drosophila meeting abstract
MABST|We have conducted a systematic analysis of human disease gene homologues in
| Drosophila melanogaster with the goal of identifying cases where the
| powerful molecular genetic tools available in Drosophila could be best used
| to greatest advantage in analyzing the human disease condition. Based on
| our analysis, we have initiated experimental studies into several human
| disease genes in Drosophila including those causing primary congenital
| glaucoma (CYP1B1 = Drosophila cyp18), the gene causing Angelman syndrome,
| and two genes potentially involved in Alzheimer's disease (TSA and PAG,
| which encode proteins that bind Presenilin). The objective of our PCG
| studies is to identify potential candidate genes in Drosophila
| corresponding to a suppressor locus on the short arm of chromosome 8 that
| can suppress the effects of mutations in CYP1B1 in a sub-population of
| Saudis. We have generated a series of mutant alleles in the Drosophila
| cyp18 gene which result in fluid flow problems reminiscent of those
| involved in PCG and are screening for second site suppressors of these
| mutations. We will determine whether any of the suppressors loci we
| identify in Drosophila have human homologues mapping to the short arm of
| human chromosome 8. We will then collaborate with Dr. B. Bejjani to ask
| whether any of these genes may correspond to the suppressor locus he is has
| mapped to 8p. In the case of the Angelman syndrome gene, which encodes E3
| ligase protein that targets selected proteins for degradation, we will
| screen for suppressors of loss-of-function mutations in the Drosophila
| Angelman syndrome (das) gene that cause lethality or semi -lethality in
| Drosophila and then collaborate with Dr. A. Beaudette's group to determine
| whether human or murine counterparts of these proteins are present in
| elevated levels in a human Angelman patient sample or in an Angelman model
| mouse. Finally, in the case of the novel genes interacting with Psn, we wil
| l collaborate with Dr. C. Von Broekhoven to determine whether any human
| homologs of these genes are map to candidate Alzheimer loci. From
| experimental approaches of this kind, we hope to validate Drosophila as a
| powerful model system for answering important unresolved questions in human
| medical genetics.
AU|Bier
|E.
AU|Reiter
|L.
YR|2001
TI|How best to use Drosophila as a tool for analyzing human diseases.
JR|Bellen, Taylor, 2001
PG|170
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144483	AU 1 Bissonnette et al.	YR 1 2001	TP 1 Abstract	TI 1 Characterization of a new allele of the gene twins (tws430).	REFM 1 Bellen, Taylor, 2001: 121		
ID|FBrf0144483
TP|abstract
|Drosophila meeting abstract
MABST|We have identified a new allele of the gene twins, a gene coding for a 55kd
| regulatory subunit of the enzyme Protein Phosphatase 2A (PP2A). This
| mutation disrupts both peripheral (PNS) and central (CNS) nervous system
| development of the adult Drosophila melanogaster, with no affect on
| embryonic development. Within the CNS, neuroblasts in the thoracic ganglion
| and central brain fail to enter the cell cycle and produce no progeny,
| while optic lobe neuroblasts do divide producing progeny. PNS phenotypes
| include a loss of occipital hairs and a decrease in the number of
| dorsal-central and s cutellar hairs on the thorax. PP2A has been shown to
| play a role in PNS development of the post-embryonic fly. In the PNS, a
| sensory organ precursor (SOP) undergoes one symmetric division, which is
| followed by a single division of the progeny. The result is four cells that
| differentiate into the sensory hair and socket on the external side of the
| cuticle, and the neuron and sheath cell on the interior. PP2A is involved
| in specifying one of these fates to the four progeny. This new allele of
| twins shows a disrupted pattern of sensory hair distribution. We believe
| PP2A plays an additional role, acting earlier to help specify the field of
| cells that become SOP's. This new allele of twins will help better define
| the role of PP2A in post-embryonic development of the PNS and CNS.
AU|Bissonnette
|D.M.
AU|Ng
|D.M.
AU|Booker
|R.
YR|2001
TI|Characterization of a new allele of the gene twins (tws430).
JR|Bellen, Taylor, 2001
PG|121
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144484	AU 1 Blau et al.	YR 1 2001	TP 1 Abstract	TI 1 The role of VRILLE and PDP1 in circadian rhythms.	REFM 1 Bellen, Taylor, 2001: 95		
ID|FBrf0144484
TP|abstract
|Drosophila meeting abstract
MABST|Clock genes form a negative feedback loop that regulates cycling expression
| of their own genes in pacemaker cells. These pacemaker cells presumably
| then release signals at different times of day that tell the fly when to be
| active and when to sleep. We previously identified a transcription factor
| called vrille on the basis of its rhythmic clock-dependent expression.
| Cycles of vrille RNA and protein are required for a functional clock since
| over-expression of vrille causes molecular and behavioral arrhythmicity.
| How does VRILLE feed back to the clock? Our results indicate that VRILLE
| directly regulates cycling of the dClock gene, whose RNA and protein levels
| also oscillate in a clock-dependent manner. VRILLE is likely to act as a
| transcriptional repressor of dClock expression. What then activates dClock
| expression? We searched for VRILLE-related genes and found Par Domain
| Protein 1 (Pdp1), a gene which encodes a transcription factor with an
| almost identical DNA-binding domain to VRILLE, and whose expression is also
| clock-dependent. Over-expression of wild type Pdp1 causes arrhythmicity, as
| does over-expression of a dominant-negative form of Pdp1 � indicating that
| Pdp1 is a likely new clock gene. We are testing the hypothesis that VRILLE
| and PDP1 proteins have opposite effects on the dClock promoter, and are
| responsible for regulating cycles of dClock expression.
AU|Blau
|J.
AU|Cyran
|S.
AU|Buschsbaum
|A.
AU|Lin
|M.
AU|Reddy
|K.
AU|Storti
|B.
YR|2001
TI|The role of VRILLE and PDP1 in circadian rhythms.
JR|Bellen, Taylor, 2001
PG|95
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144485	AU 1 Block et al.	YR 1 2001	TP 1 Abstract	TI 1 Clonal analysis of embryonic and post-embryonic neurogenesis in the ventral nerve cord.	REFM 1 Bellen, Taylor, 2001: 181		
ID|FBrf0144485
TP|abstract
|Drosophila meeting abstract
MABST|The generation of the central nervous system in Drosophila occurs in two
| waves, with more than 90% of the adult CNS being produced
| post-embryonically. Despite its clear importance, little is known regarding
| postembryonic neurogenesis in the ventral nerve cord. This is largely due
| to technical difficulties, which until recently have prevented the study of
| neuroblasts (NBs) past their earliest divisions. We have used the MARCM
| technique to analyse both embryonic and post-embryonic neurogenesis in the
| ventral nerve cord. This has enabled NB lineages to be determined, from
| first division to last. By creating clones at different time points during
| development, we are able to examine progressive changes in the neuron types
| produced by a single NB and determine whether there are significant
| transitions between embryonic and post -embryonic clones. Significantly,
| motorneurons have been found to be produced post -embryonically in thoracic
| and terminal segments, which are specialised for adult specific behaviours,
| but have not so far been observed in abdominal segments. The ongoing
| analysis will enable key questions regarding neurogenesis and the
| functional organisation of the adult ventral nerve cord to be addressed.
| For example, do clonally related neurons innervate common regions of
| neuropile or share common functional roles? Is there a relationship between
| NB position and the central organisation of its progeny? Do the properties
| of neurons in a clone change as the lineage progresses? Are all NBs
| multipotent? Is the somatotopic and modality specific organisation of
| sensory afferents mirrored in the organisation of the central nervous
| system? Is there a corresponding anatomical segregation of interneurons?
| Preliminary results will be presented.
AU|Block
|L.
AU|Williams
|D.
AU|Shephard
|D.
YR|2001
TI|Clonal analysis of embryonic and post-embryonic neurogenesis in the ventral nerve cord.
JR|Bellen, Taylor, 2001
PG|181
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144486	AU 1 Botella et al.	YR 1 2001	TP 1 Abstract	TI 1 Identification of novel genes and mechanisms of neurodegeneration in Drosophila.	REFM 1 Bellen, Taylor, 2001: 165		
ID|FBrf0144486
TP|abstract
|Drosophila meeting abstract
MABST|In the last years Drosophila melanogaster has been proved useful for the
| study of basic mechanisms of neurodegeneration. While some groups have used
| it successfully to model some known neurodegenerative diseases, we have
| tried to identify and study novel genes involved in mechanisms of
| age-related neurodegenerative disorders. Several histological screens have
| been performed to isolate mutants that show brain degeneration. Here we
| present two cases of our best studied mutants in which neuronal
| degeneration occurs via different mechanisms: Total and partial
| loss-of-function mutation in the Drosophila gene RasGAP (vap), a negative
| regulator of the Egfr/ Ras pathway, lead to age-related neuronal
| degeneration with a morphology resembling that of cell death type 2
| (autophagy). We show that mutations in RasGAP cause an aberrant regulation
| of RAS that leads to a deregulated activation of the MAPK transduction
| cascade. Thus our results on the vap mutant provide new insights into the
| role of this signal transduction cascade in the maintenance of the
| Drosophila adult nervous system and a useful model to study autophagy in
| the context of neuronal cell death. >From the same screen we have also
| isolated sniffer, a member of the short-chain dehydrogenases/ reductases
| family. In sniffer mutants the phenotype is especially evident in the
| cortex of the first optic ganglion, the lamina, where neurons die in an
| age-dependent manner followed by apoptosis of glial cells. Mutant flies
| show, besides brain degeneration, a locomotor phenotype and reduced life
| span. We show that the function of sniffer is required to prevent neuronal
| apoptosis induced by oxidative stress. Further characterization of this
| mutant together with experiments to elucidate the function of this enzyme
| will be presented. The analysis of sniffer provides an important model to
| get insights into the causal mechanisms of oxidative stress in the process
| of neurodegeneration and life span.
AU|Botella
|J.A.
AU|Kretzschmar
|D.
AU|Kiermayer
|C.
AU|Hughes
|D.
AU|Becker
|K.
AU|Schneuwly
|S.
YR|2001
TI|Identification of novel genes and mechanisms of neurodegeneration in Drosophila.
JR|Bellen, Taylor, 2001
PG|165
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144487	AU 1 Boyle and Thomas	YR 1 2001	TP 1 Abstract	TI 1 Analysis of the role of Eph RTK, dek in axon pathfinding and target recognition in the embryonic CNS.	REFM 1 Bellen, Taylor, 2001: 206		
ID|FBrf0144487
TP|abstract
|Drosophila meeting abstract
MABST|Studies of the large family of vertebrate Eph receptor tyrosine kinases and
| their ligands, the Ephrins, have implicated a role for this gene family in
| axon guidance. In Drosophila, there is a single Eph family member, named
| DEK, which exhibits equal similarities to both the EphA and EphB subclasses
| of receptors. Consistent with a possible role in axon guidance, DEK is
| restricted to the embryonic CNS at a time when neurons are extending axons
| and is targeted to axons and growth cones. A search of the Drosophila
| genome database uncovers a single EPHRIN that contains regions of homology
| to both vertebrat e type A and type B ligands. Curiously, we have found by
| in situ hybridization that ephrin, like dek, is expressed throughout the
| embryonic CNS. To determine their roles in nervous system development, we
| have used a P element mobilization scheme to generate mutations in dek and
| ephrin. Both genes map within 42 Kb of one another on the 4th chromosome.
| We mobilized a lethal P element located 155 Kb away from dek and selected
| those insertions that both reverted the lethality (thus indicating a
| mobilization event) and mapped by linkage to the 4th chromosome. Insertion
| sites for each of the lines generated were determined by sequencing
| fragments generated by inverse PCR. From the 55 lines generated, we
| recovered an insertion, P114, that maps 3 kb upstream of t he dek
| transcriptional start site. P114 is currently being used to generate
| excisions deleting the dek coding sequences. The consequence of loss of dek
| function on neuronal development will be presented.
AU|Boyle
|M.
AU|Thomas
|J.
YR|2001
TI|Analysis of the role of Eph RTK, dek in axon pathfinding and target recognition in the embryonic CNS.
JR|Bellen, Taylor, 2001
PG|206
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144488	AU 1 Phelps et al.	YR 1 2001	TP 1 Abstract	TI 1 Asymmetric cell division in the embryonic CNS.	REFM 1 Bellen, Taylor, 2001: 9		
ID|FBrf0144488
TP|abstract
|Drosophila meeting abstract
MABST|One way to generate diversity is to ensure that when a cell divides each of
| its daughters assumes a distinct identity. This can be simply achieved by
| segregating a cell fate determinant to only one of the two daughter cells
| at cell division. Prior to neuroblast cell division, Prospero and its mRNA
| are localised to the basal cortex and are partit ioned to the GMC at
| cytokinesis. Prospero is then released and enters the nucleus where it
| regulates genes that direct GMC fate. We are investigating the molecular
| mechanisms that direct the asymmetric segregation of cell fate determinants
| and their mRNAs. The coiled-coil domain protein, Miranda, is essential for
| the segregation of both Prospero protein and its mRNA. Miranda binds
| directly to Prospero and to Staufen, which in turn binds Prospero mRNA.
| Studies in which the actin cytoskeleton is disrupted demonstrate that
| F-actin is essential for localisation of Miranda. The dynamics of
| asymmetric localisation and the dependence on F-actin suggest a role for
| myosin motor proteins in asymmetric cell division. We have shown that
| cytoplasmic myosin II plays an integral role in localising determinants in
| neuroblasts. Myosin II is itself localised asymmetrically in neuroblasts,
| and appears to preclude binding of determinants to the apical cortex.
| Myosin II is the homologue of C. elegans NMY-2, which is required to
| localise PAR proteins in the one-cell embryo (Guo and Kemphues, 1996),
| revealing a conserved role for myosin II motors in mediating
| actin-dependent asymmetric segregation. In Drosophila, myosin II has been
| shown to interact directly with the tumour suppressor Lethal giant larvae,
| which is also required for asymmetric cell division (Ohshiro et al., 2000;
| Peng et al., 2000). We are using time lapse confocal microscopy to follow
| cell fate determinants and cytoskeletal proteins simultaneously in living
| embryos. For theses experiments, we have fused different spectral variants
| of GFP to Miranda, Prospero, Staufen and Myosin, actin and microtubules.
AU|Phelps
|C.B.
AU|Barros
|C.
AU|Brand
|A.H.
YR|2001
TI|Asymmetric cell division in the embryonic CNS.
JR|Bellen, Taylor, 2001
PG|9
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144489	AU 1 Brody et al.	YR 1 2001	TP 1 Abstract	TI 1 A cDNA screen for genes that are dynamically expressed during the generation of embryonic neural lineages.	REFM 1 Bellen, Taylor, 2001: 64		
ID|FBrf0144489
TP|abstract
|Drosophila meeting abstract
MABST|During neuroblast (NB) lineage development, temporally ordered transitions
| in NB gene expression have been shown to accompany the changing repertoire
| of functionally diverse cells generated by NBs. For example, we have
| described a transcription factor network, the Hb-> Pdm-> Cas-> Gh
| cascade 1,2 , that regulates temporal transitions in gene expression during
| CNS lineage development. In order to discover additional components of this
| network, both upstream and downstream, we have carried out an expression
| screen. A cDNA library was prepared from 2,600 individually dissected 8.5h
| (stage 11) embryonic heads. The unamplified library was screened to remove
| widely expressed sequences. cDNAs corresponding to 4,500 temporally
| regulated genes have been partially sequenced to determine the
| corresponding genes. We have subsequently carried out over 2,000 in situ
| hybridizations in order to discover which of these genes are expressed in
| neural precursors. Our expression studies have revealed 57 new or partially
| characterized genes that are dynamically expressed during CNS development.
| The expression patterns of these CNS lineage markers will be presented.
| Most of these genes have been predicted by the Drosophila genome project, a
| few have already been cloned, but some are undefined, that is they were not
| among the genes predicted by the Drosophila genome project. In addition, we
| provide information on 823 known and 1,621 previously uncharacterized genes
| whose corresponding cDNAs have been identified in the screen. Information
| about all of these genes is available at the web site entitled "BrainGenes:
| a search for Drosophila neural precursor genes": http:// sdb. bio. purdue.
| edu/ fly/ brain/ ahome. htm. We will describe addit-ional experiments
| designed to reveal the temporal regulation of these and other CNS
| determinates. 1. Kamgadur, et al. Genes & Development 12: 246-260
| (1998) 2. Brody and Odenwald, Developmental Biology, 226: 34-44 (2000)
AU|Brody
|T.
AU|Stivers
|C.
AU|Nagel
|J.
AU|Odenwald
|W.F.
YR|2001
TI|A cDNA screen for genes that are dynamically expressed during the generation of embryonic neural lineages.
JR|Bellen, Taylor, 2001
PG|64
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144490	AU 1 Broihier and Skeath	YR 1 2001	TP 1 Abstract	TI 1 Homeodomain protein extra-extra: The Drosophila Hb9 homolog, directs neuronal fate via cross-repressive and cell non-autonomous mechanisms.	REFM 1 Bellen, Taylor, 2001: 10		
ID|FBrf0144490
TP|abstract
|Drosophila meeting abstract
MABST|To initiate a systematic analysis of the genetic basis of neuronal fate
| determination, we undertook a saturation mutagenesis to identify genes that
| regulate the development of a specific set of CNS neurons. Here we present
| the identification and characterization of one mutant isolated in this
| screen, extra-extra (exex). exex is the sole Drosophila homolog of the
| closely-related vertebrate genes Hb9/ MNR2, which encode homeodomain
| factors required for motorneuron (MN) development. We identified exex via
| its ability to repress Even-skipped (Eve), a homeodomain protein expressed
| in all dorsally-projecting MNs in the Drosophila embryonic CNS. We find
| that Exex is expressed in ventrally-projecting MNs and is required for
| their differentiation. Furthermore, we demonstrate that Exex and Eve are
| expressed in mutually-exclusive patterns and repress each other to
| distinguish ventrally and dorsally-projecting MNs. Lastly, we show that
| exex is required to repress the LIM homeodomain protein Lim3 in a subset of
| dorsally-projecting MNs. As these MNs express Eve, and not Exex, Exex acts
| cell non-autonomously to restrict lim3 expression.
AU|Broihier
|H.T.
AU|Skeath
|J.B.
YR|2001
TI|Homeodomain protein extra-extra: The Drosophila Hb9 homolog, directs neuronal fate via cross-repressive and cell non-autonomous mechanisms.
JR|Bellen, Taylor, 2001
PG|10
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144491	AU 1 Bronk et al.	YR 1 2001	TP 1 Abstract	TI 1 Different domains mediate different functions of Drosophila cysteine-strong protein at nerve terminals.	REFM 1 Bellen, Taylor, 2001: 22		
ID|FBrf0144491
TP|abstract
|Drosophila meeting abstract
MABST|Multiple steps, vesicle fusion, Ca 2+ entry, and Ca 2+ clearance, might be
| regulated by the synaptic vesicle-associated cysteine-string protein (CSP).
| Null mutations in Drosophila csp increase stimulus -evoked presynaptic Ca
| 2+ levels but reduce evoked release at larval neuromuscular junctions. 1
| Therefore, we hypothesize that CSP increases release by promoting a
| downstream step of Ca 2+ -triggered fusion, and maintains appropriate Ca 2+
| levels by regulating Ca 2+ entry and/ or clearance. To better understand
| CSP's action, we initiated a systematic in vivo structure/ function study.
| Specifically, we analyzed the effects of expressing mutant CSP's lacking
| the following conserved domains at csp null terminals: (1) the J-domain
| mediating the CSP-Hsc70 interaction and (2) the "linker domain" (L-domain)
| whose protein interactions are unknown. Expression of ?J-CSP restored
| normal levels of evoked neurotransmitter release in csp nulls at 23 o C,
| but did not restore viability. ?J-CSP expression also did not revert the
| elevated resting Ca 2+ levels at 34 o C, which are characteristic of csp
| null mutants. Interestingly, ?J-CSP expression caused a 4-fold increase in
| spontaneous mEJP frequency at 32 o C, while csp null mutants showed a
| normal frequency. This "additional" defect is consistent with the idea that
| ?J-CSP expression restores Ca 2+ triggered fusion in csp nulls, but not the
| intraterminal resting Ca 2+ levels at elevated temperatures. In contrast to
| ?J-CSP, ?L-CSP expression restored normal transmission at 23 o C and normal
| resting Ca 2+ levels at 34 o C but not viability. In addition,
| intraterminal Ca 2+ levels were still increased upon nerve stimulation. Our
| current results show that different domains of CSP mediate different
| functions at nerve terminals. Surprisingly, the J -domain is not essential
| for Ca 2+ triggered fusion but rather for Ca 2+ entry/ extrusion. Ca 2+
| entry/ extrusion is affected differently by ?J-CSP and ?L-CSP, but it
| remains to be seen whether this difference is due to a change in the rate
| of Ca 2+ entry, Ca 2+ clearance, and /or to a different "set point" for the
| regulation of Ca 2+ homeostasis. Future work will resolve whether these
| domains mediate the known interactions of CSP with Ca 2+ channels,
| G-proteins, and syntaxin.
AU|Bronk
|P.
AU|Dawson-Scully
|K.D.
AU|Nie
|Z.
AU|Atwood
|H.L.
AU|Zinsmaier
|K.E.
YR|2001
TI|Different domains mediate different functions of Drosophila cysteine-strong protein at nerve terminals.
JR|Bellen, Taylor, 2001
PG|22
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144492	AU 1 Burnette and Hirsh	YR 1 2001	TP 1 Abstract	TI 1 Identification of neurons modulating responses to crack cocaine in Drosophila.	REFM 1 Bellen, Taylor, 2001: 96		
ID|FBrf0144492
TP|abstract
|Drosophila meeting abstract
MABST|We are using Drosophila as a model to identify novel genetic pathways
| involved in modulating responses to crack cocaine. Wild type flies
| repeatedly exposed to the same dose of cocaine show enhanced responses, a
| process known as sensitization. Previous results have shown that the
| circadian gene products period, clock, and cycle fail to sensitize and thus
| are required for sensitization, whereas timeless has no role in the process
| (Andretic et al. Science (1999) 285( 5430): 1066-8285). This suggests that
| there is a subset of period expressing cells involved in cocaine response
| modulation but is outside of the clock. To further differentiate between
| the clock mechanism and cocaine responses we are examining cocaine
| responses subsequent to transiently blocking synaptic transmission using
| the UAS-shi ts1 system. We have driven the expression of UAS-shi ts1 with a
| GAL4 driver that expresses in most dopa decarboxlyase expressing cells.
| When raised and tested at the permissive temperature, these flies show
| normal locomotor responses to the initial dose of cocaine. Flies raised at
| the permissive temperature but tested at 24? C show greatly reduced
| responses to cocaine. This result is consistent with findings in mammals
| and flies that transiently blocking dopamine signaling reduces locomotor
| responses to cocaine. Flies raised and tested at 24? C are hypersensitive
| to cocaine, which suggests that developmental compensation has taken place,
| as observed previously when tetanus toxin expression was driven with
| Ddc-GAL4 drivers (Li et al (2000). Curr. Biol. 10( 4): 211-4). Flies
| hemizygous for per-GAL4 and UAS-shi ts1 insertions are hypersensitive to
| cocaine and surprisingly, become resistant upon repeated exposures when
| grown and tested at 24? C. This differs from the per 01 , which remains
| equally responsive after repeated exposures. We will conduct an enhancer
| trap screen to identify specific neurons involved in modulating cocaine
| responses. We will also determine whether neurons of the central circadian
| oscillator are required for the modulation of cocaine responses using the
| pdf-GAL4 and other available GAL4 insertion lines.
AU|Burnette
|J.
AU|Hirsh
|J.
YR|2001
TI|Identification of neurons modulating responses to crack cocaine in Drosophila.
JR|Bellen, Taylor, 2001
PG|96
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144493	AU 1 Cai et al.	YR 1 2001	TP 1 Abstract	TI 1 D-Homer function is required for telophase rescue in Drosophila embryonic neuroblast divisions.	REFM 1 Bellen, Taylor, 2001: 148		
ID|FBrf0144493
TP|abstract
|Drosophila meeting abstract
MABST|Asymmetric divisions of neural ste m cells, neuroblasts (NBs) produce
| diverse neural cell types required for the central nervous system
| formation. It has been suggested that two asymmetry-controlling mechanisms,
| Insc -dependent and Insc-independent, are involved in NB division. During
| NB divisions, a group of apically localized proteins, such as Bazooka
| (Baz), Inscuteable (Insc) and Partner of Inscuteable (Pins) forms an apical
| complex and controls various downstream events of asymmetric divisions. In
| the mutants that apical complex is defective, the basal localization of
| cell fate determinants in dividing NBs is affected during early phases of
| mitosis. However, late in mitosis the cell fate determinants are
| redistributed to and enriched in the basal/ lateral cortex of mutant NBs
| from where the future ganglion mother cells (GMCs) will "bud" off. This
| Insc-independent phenomenon has been referred to as "telophase rescue". The
| mechanism of "telophase rescue" is not clear at present. We have cloned the
| d-homer, the Drososphila homolog of homer gene in mammals. D-Homer contains
| a conserved amino-terminal EVH-1 domain and a carboxyl-terminal motif with
| a predicted coiled-coil (CC) structure. During early neurogenesis the
| sub-cellular localization of D-Homer in dividing NBs is cell cycle
| regulated. In interphase neuroblasts, D-Homer is distributed evenly
| throughout cell cortex. However, once NBs enter mitosis, localization of
| D-Homer becomes asymmetric. D-Homer is enriched to the apical cortex of
| mitotic NBs in prophase. In metaphase, D-Homer forms an apical crescent and
| remains apical throughout the rest of mitosis. The asymmetric D-Home
| localization is Insc-independent. Two viable deletion lines were recovered
| from the imprecise excision of the EP-element insertion line and both
| deletions are antigen-minus as judged by antibody staining, suggesting that
| D-Homer is not essential for animal viability. Homozygous d-homer does not
| show any obvious phenotypes in asymmetric NB divisions. However, when
| d-Homer is removed in insc mutant, basal proteins, such as Mir/ Pro and
| Pon/ Numb, are evenly distributed to the cortex of the dividing NBs and the
| redistribution of basal proteins to the future GMC budding site (telophase
| rescue) does not occur. This observation suggests that d-Homer could be the
| first identified member of the Insc-independent mechanism that is
| responsible for the "telophase rescue".
AU|Cai
|Y.
AU|Yu
|F.
AU|Chia
|W.
AU|Yang
|X.
YR|2001
TI|D-Homer function is required for telophase rescue in Drosophila embryonic neuroblast divisions.
JR|Bellen, Taylor, 2001
PG|148
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144494	AU 1 Adachi et al.	YR 1 2001	TP 1 Abstract	TI 1 Expression of eyeless in the Drosophila brain depends on a complex of enhancers.	REFM 1 Bellen, Taylor, 2001: 182		
ID|FBrf0144494
TP|abstract
|Drosophila meeting abstract
MABST|The Drosophila Pax-6 homolog eyeless plays an important role in the
| development of several brain neuropils including the mushroom bodies,
| central complex, and optic lobes. Analysis of Eyeless distribution in
| embryonic, larval, pupal, and adult brains suggests that the expression of
| eyeless in the various neuropils is governed by separable,
| neuropil-specific enhancer elements. To start to address how complex brains
| are generated by the region-specific expression of transcription factors,
| and of their transcriptional target genes, we pursued the transcriptional
| regulation of eyeless. We have characterized the GAL4 enhancer trap line
| OK107 as an insertion in the eyeless upstream region that reproduces many
| critical features of the eyeless expression pattern in the brain. To
| further identify individual, neuropil -specific regulatory sequences, a
| detailed analysis of the upstream region and the first and second intron of
| the eyeless gene was performed using in vivo reporter gene analysis. We
| have identified DNA elements of the eyeless gene that generate preferential
| expression in the central brain, and the mushroom bodies in particular, and
| the optic lobes. A detailed analysis of the mushroom body expression
| pattern with various markers reveals that expressio n in the different
| neuropils appears to depend on several physically distinct regulatory
| sequences that interact to generate the final pattern. Sequence analysis of
| the regulatory elements has identified candidate upstream factors that are
| being tested. This study will be very valuable not only to understand the
| transcriptional circuitry that generates complex brain centers, but also to
| generate tools for molecular and genetic interference with integrated
| neural processes such as vision, or learning and memory.
AU|Adachi
|Y.
AU|Clements
|J.
AU|Hauck
|B.
AU|Kang
|Y.Y.
AU|Kawauchi
|H.
AU|Walldorf
|U.
AU|Furukubo-Tokunaga
|K.
AU|Callaerts
|P.
YR|2001
TI|Expression of eyeless in the Drosophila brain depends on a complex of enhancers.
JR|Bellen, Taylor, 2001
PG|182
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144495	AU 1 Carlo et al.	YR 1 2001	TP 1 Abstract	TI 1 Molecular analysis of the fruitless stimulation factor LOCUS.	REFM 1 Bellen, Taylor, 2001: 97		
ID|FBrf0144495
TP|abstract
|Drosophila meeting abstract
MABST|The original fruitless mutant was obtained from an X-ray mutagenesis screen
| as a male sterile. This fru 1 mutant contains a short inversion: In( 3R)
| 90C; 91B. The distal breakpoint is now called fru 1 , in that other
| fru-mutant alleles are located in 91B. At least three distinct phenotypes
| are caused by homozygousity for both breakpoints in the fru 1 inversion.
| First, males are behaviorally sterile; they do not curl their abdomens in
| attempts to copulate. Second, they form male-exclusive courtship chains.
| Third homozygotes and to a degree fru 1 /+ heterozygotes elicit courtship
| from normal males. The first two phenotypes were mapped to the lesion in
| 91B. The latter phenotype has been attributed to the 90C region; this
| putative genetic locus has been named fruitless stimulation factor ( fsf)
| and is the subject of the studies reported here. . Analysis of fsf has the
| potential to provide useful information about courtship stimuli, because.
| hemizygosity for the breakpoint at this locus in males caused them to be
| courted by other males. A mature wild-type male is barely courted,
| suggesting that the fsf locus controls a factor involved in establishing
| the non-stimulating features of normal maleness. We suggest further that
| understanding the gene whose existence is implied by the fsf breakpoint
| will provide specific insights into pheromonal courtship stimuli, given
| that paralyzed fsf/ 90C-deletion males elicit extremely high levels of
| courtship, whereas immobilized wild-type males are almost completely
| ignored. Using ligation-mediated PCR; we have cloned both the distal and
| proximal ends of the fru 1 inversion and have mapped the breakpoints down
| to the nucleotide level. The centromere-distal end of the inversion in 91b
| maps about 3 kb upstream of a proposed fru transcription start site within
| that (91B) locus (the so-called P1 such site, located ca. 130 kb upstream
| of the fru ORF). The proximal end of the inversion has been located within
| the Celera genomic sequence. This 90C breakpoint occurred between two
| transcribed regions. The expressed sequence proximal to the breakpoint has
| strong homology to a mammalian gene called Rab-interacting-molecule (Rim).
| RIM protein has been demonstrated to be regulator of RAB3 in mammals; the
| latter is involved the fusion of vesicles to the cell membrane. RIM is
| represented by several non-identical EST's in the Drosophila database.
| Northern analysis has demonstrated that numerous transcripts can be
| detected with a probe to a common region of Drosophila RIM, mRNA
| heterogeneity that is likely to arise from multiple promoters and
| alternative splicing. RIM is a good candidate for being the gene
| responsible for the fsf phenotype. The second expressed sequence, located
| distal to the breakpoint, is the previously characterized couch potato
| (cpo) gene, which encodes a widely expressed RNA-binding protein associated
| (in viable hypomorphic cpo mutants) with general sluggishness. To help
| determine which of these two transcription units is associated with the fsf
| phenotype, a P-element located within the cpo transcription unit was
| excised. Of the 54 lines obtained that were homozygous viable and no longer
| express the transposon marker, 15 produced males that were sterile when
| homozygous for the newly derived 3rd chromosome. Homozygous females from
| all such lines were fertile. Therefore, cpo may play a role in male
| fertility, a phenotype in the same ballpark as establishment normal male
| (fsf + ) pheromones. These excision lines are being tested to determine
| whether homozygous males can elicit courtship from wild type males and to
| assess the cause of the male sterility (e. g., pre-mating behavioral
| deficits vs. defective sperm). Molecularly these lines are being
| characterized to determine which genes were effected by the P-element excisions.
AU|Carlo
|T.
AU|Villella
|A.
AU|Hall
|J.C.
YR|2001
TI|Molecular analysis of the fruitless stimulation factor LOCUS.
JR|Bellen, Taylor, 2001
PG|97
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144496	AU 1 Carney and Taylor	YR 1 2001	TP 1 Abstract	TI 1 A putative vesicle cargo receptor protein is required for female oviposition behavior.	REFM 1 Bellen, Taylor, 2001: 176		
ID|FBrf0144496
TP|abstract
|Drosophila meeting abstract
MABST|Little is known about how sex-specific nervous systems are created and
| produce a desired behavioral outcome. We have approached this problem in
| the Drosophila female by screening for genes involved in female-specific
| mating or oviposition behaviors, with the hope of identifying genetic
| cascades functioning in sex-specific neuronal differentiation and signal
| transmission. Mutations in a newly identified gene result in the loss of
| oviposition behavior and the retention of phenotypically normal eggs in the
| oviducts of mated mutant females. Sequence analysis reveals that this gene
| has homology to a family of vesicle cargo receptor proteins found in
| numerous taxa. It is expressed in both adult females and males, potentially
| in a sex-specific manner. Two independent P element insertion alleles
| abolish all identified transcripts but produce an obvious phenotype only in
| females. Enhancer trap analysis of adult females from each P line reveals
| expression in the central nervous system but not other tissues. However, in
| situ analysis of sectioned adult females indicates that transcripts
| predominantly localize to ovarian follicle cells. Currently, only two other
| genes are known whose mutant phenotypes include egg retention.
| dissatisfaction (dsf )is an output gene of the sex determination hierarchy
| that is needed for receptivity to mating as well as oviposition behavior.
| Tyramine Beta-Hydroxylase (TBH) is needed for production of the
| neurotransmitter octopamine, which functions in egg-laying behavior.
| Genetic and molecular data suggest that the putative cargo receptor
| functions outside of either of these two pathways and may be a component of
| another, parallel signaling pathway needed for oviposition.
AU|Carney
|G.E.
AU|Taylor
|B.J.
YR|2001
TI|A putative vesicle cargo receptor protein is required for female oviposition behavior.
JR|Bellen, Taylor, 2001
PG|176
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144497	AU 1 Leaman and Carthew	YR 1 2001	TP 1 Abstract	TI 1 The function and dysfunction of CDK5 in neuronal development and degeneration.	REFM 1 Bellen, Taylor, 2001: 166		
ID|FBrf0144497
TP|abstract
|Drosophila meeting abstract
MABST|One of the neuropathological hallmarks of Alzheimers Disease (AD) is the
| presence of neurofibrillary tangles (NFT) that are composed of aggregates
| of the protein Tau in abnormal conformations and phosphorylation states.
| The mammalian kinase CDK5 phosphorylates Tau in vitro and is thought to
| play a role in Tau's transition into NFTs. Here we explore the role of
| Drosophila CDK5 and its activator protein Dp35 in neuronal development and
| degeneration. We find that CDK5 and Dp35 are required in embryonic CNS
| neurons for growth cone guidance and motility. We also find axon branching
| is normally suppressed by the action of CDK5. We present genetic evidence
| that places CDK5 activation downstream of growth cone guidance cues
| received by neurons of the CNS. Tissue from AD brains contains a
| proteolyzed form of human p35 in which its myristoylation signal is cleaved
| off, resulting in abnormal cellular distribution of the smaller p25. We
| expressed a truncated form of Dp35 in Drosophila neurons that structurally
| mimics the AD p25 fragment. Dp25 expression during development resulted in
| impaired development of the adult CNS projection systems and a block in
| eclosion behavior. In contrast Dp35 expression had no effect nor did Dp25
| expression in non-neuronal tissues. The Dp25 gain-of-function phenotype was
| suppressed by reducing the dosage of the cdk5 gene, suggesting that CDK5 is
| necessary for the neuronal dysfunction. Dp25 expression after adult
| eclosion resulted in reduced lifespan and neuronal apoptosis. In animals
| that co-expressed human Tau protein, these effects were accompanied by
| hyperphosphorylation of human Tau and its conformational change to a
| pre-NFT state. Co-expression of human Tau and full-length Dp35 had no
| adverse affect on Tau or neuronal viability. These data strongly support a
| causative relationship between structural changes in p35 and Tau that
| precede neuronal degeneration.
AU|Leaman
|D.
AU|Carthew
|R.
YR|2001
TI|The function and dysfunction of CDK5 in neuronal development and degeneration.
JR|Bellen, Taylor, 2001
PG|166
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144498	AU 1 Castro et al.	YR 1 2001	TP 1 Abstract	TI 1 Repression by Su(H) in Notch-mediated lateral inhibition.	REFM 1 Bellen, Taylor, 2001: 122		
ID|FBrf0144498
TP|abstract
|Drosophila meeting abstract
MABST|Notch (N) signaling plays a critical role in a wide variety of cell fate
| decisions during development. It is used to specify distinct cell fates
| among interacting cells and occurs in three general settings: 1) between
| rows of juxtaposed cells in which each row adopts a distinct fate; 2)
| binary cell fate decisions between sister cells in asymmetric cell
| divisions; and 3) cell fate decisions wherein a single cell uses N
| signaling to laterally inhibit surrounding cells from adopting its fate.
| The canonical N pathway involves two interacting cells: Delta ligand on the
| non-responding cell binds N receptor on the responding cell, inducing
| proteolytic cleavage and nuclear translocation of the N intracellular
| domain, which then complexes with the ubiquitously expressed transcription
| factor Suppressor of Hairless [Su( H)] to activate N target genes. While
| earlier models depicted Su( H) as having a strictly activating role in N
| responder cells, recent evidence has shown that Su( H) has an additional
| and critical repressive role in non-responders, serving to repress N target
| genes in the se cells. This repressive function of Su( H) has been shown in
| N signaling between rows of cells (Morel et al.) and during binary cell
| fate decisions (our lab; Barolo et al.). Recently, we have been able to
| demonstrate that this novel repression function also plays a role in
| lateral inhibition, the third setting of N signaling. During imaginal disc
| development, clusters of cells (proneural clusters, PNC) defined by their
| expression of proneural proteins (PN) are formed. One cell is selected to
| become a committed N non-responder, signaling the responding cluster cells
| to express N target genes (such as those of the Enhancer of split [E( spl)]
| Complex) which repress PN levels in these cells. PNs therefore accumulate
| to high levels in the non-responder and confer on it the sensory organ
| precursor (SOP) fate. The SOP then divides to give rise to a mechanosensory
| bristle. Using an enhancer-reporter construct, derived from the E( spl) ma
| gene, that expresses strictly in non-SOP (responder) cells of PNCs, we have
| found by mutational analysis that Su( H) binding sites are critical not
| only for gene activation in the non-SOP cells but also for repression in
| SOPs. Loss of this repression results in ectopic expression of the reporter
| in SOPs. This ectopic expression is furthermore directly dependent on the
| integrity of PN protein binding sites. We are currently investigating the
| nature of the repressive complex, the importance of this repression for
| preserving the SOP fate, and the ability to confer Su( H)-mediated
| repression on a heterologous enhancer that is normally active strictly in SOPs.
AU|Castro
|B.
AU|Barolo
|S.
AU|Posakony
|J.W.
YR|2001
TI|Repression by Su(H) in Notch-mediated lateral inhibition.
JR|Bellen, Taylor, 2001
PG|122
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144499	AU 1 Certel et al.	YR 1 2001	TP 1 Abstract	TI 1 Regulation of motor axon targeting by the combinatorial activity of POU and LIM homeodomain proteins.	REFM 1 Bellen, Taylor, 2001: 207		
ID|FBrf0144499
TP|abstract
|Drosophila meeting abstract
MABST|Recent studies have shown that the specification of neuronal identities is,
| in part, controlled by the combinatorial expression of transcription
| factors. Members of the LIM homeodomain (LIM-HD) and POU domain families of
| transcription factors are expressed in discrete subsets of developing
| neurons and have been shown in numerous organisms to regulate neuronal
| differentiation. Previous studies have demonstrated that two Drosophila
| LIM-HD members, islet( isl) and lim3, act in a combinatorial code to
| specify motor neuron subtype identity. Islet and Lim3 are co-expressed in a
| subset of CNS neurons including the TN and ISNb motor neurons. To identify
| factors that may act to differentiate between the TN and ISNb subgroups, we
| examined the expression pattern of characterized transcription factors. We
| found that Islet and Lim3 are co-expressed with the POU factor, Drifter, in
| the ISNb motor neuron subclass. Drifter expression is independent of Islet
| and Lim3 function indicating dfr is not a transcriptional target of these
| factors. To examine whether these proteins regulate similar aspects of
| motor axon targeting, we analyzed the ISNb nerve in trans -heterozygous
| combinations between dfr and isl and/ or lim3. Removing a single copy of
| isl, lim3 and dfr results in striking motor axon targeting defects
| characterized by reductions in muscle innervation. Specifically, the
| failure to innervate muscle cleft 12 and 13 observed in both isl 37Aa /+;
| dfr B129 /+ and lim3 Bd1 /+; dfr B129 /+ trans-heterozygotes is the most
| common phenotype of isl and lim3 mutant embryos. To further elucidate Dfr's
| role in the specification of ISNb motor neurons, we reduced the amount of
| Dfr protein through UAS-dfrdsRNA and UAS-dfr DN transgenes. Reducing Dfr
| activity causes the ISNb motor axons to leave the ventral muscle field and
| instead target the TN. In addition, misexpressing Dfr in the TN neurons
| results in a redirection of TN motor axons to the ISNb muscle target field.
| These studies suggest that Dfr may function in combination with Isl and
| Lim3 to specify muscle target selection by the ISNb motor neuron subclass.
AU|Certel
|S.J.
AU|Johnson
|W.A.
AU|Thor
|S.
YR|2001
TI|Regulation of motor axon targeting by the combinatorial activity of POU and LIM homeodomain proteins.
JR|Bellen, Taylor, 2001
PG|207
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144500	AU 1 Chen et al.	YR 1 2001	TP 1 Abstract	TI 1 Distinctive translation roles for alternative 5-UTRs in Drosophila peroxiredoxin I.	REFM 1 Bellen, Taylor, 2001: 149		
ID|FBrf0144500
TP|abstract
|Drosophila meeting abstract
MABST|Peroxiredoxin I, also discussed as nature killer cell enhance factor A and
| proliferation associate gene A, exists in organisms from E. coli to human
| and functions as antioxidant. In general, Peroxiredoxin I functions at
| least four biological incidents, i nclude thioredoxin redutase, kinase
| inhibitor, apoptosis regulator, and proliferation regulator, and also
| capable of influencing for differentiation, human immunodeficiency virus
| infection, organs transplant ischemia/ reperfusion, and skeleton
| development. In previously studies, expressing of Peroxiredoxin I mRNA was
| observed that can induced by oxidative agents and localized between central
| nervous system. In Drosophila, Peroxiredoxin I homologous gene was been
| cloned by 2D PAGE technique and validated as t hioredoxin redutase. We
| scanned expressing sequence tag datebase and found that Drosophila
| Peroxiredoxin I contains two transcriptional forms of mRNAs. Here we
| present an investigation of the mechanism of functional 5'-untranslation
| regions in Drosophila Peroxiredoxin I. In this study, we show that
| Drosophila Peroxiredoxin I contains two transcriptional forms of mRNAs that
| subsist in immensely amount in vivo. The biological functions of 5
| '-untranslation region, like efficient translation element and IRES
| activity were also presence individually in this study. The specific
| 5'-untranslation region element driven reporter lines was established and
| inspected of both reactive oxygen species and NO synthesis agents. The
| analysis shown that each 5'-untranslation region plays distinct but
| synergistic regulating role response the cellular oxidative and NO stress
| to either increase or decrease expressing of following reporter gene.
| Accordingly, the results suggest that the 5 '-untranslation regions of
| Drosophila Peroxiredoxin I play not only translation regulating events but
| also emergency roles in Drosophila central nervous system.
AU|Chen
|C.W.
AU|Lee
|D.F.
AU|Chang
|C.Y.
AU|Juang
|J.L.
YR|2001
TI|Distinctive translation roles for alternative 5-UTRs in Drosophila peroxiredoxin I.
JR|Bellen, Taylor, 2001
PG|149
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144501	AU 1 Cheng et al.	YR 1 2001	TP 1 Abstract	TI 1 Fasciclin II is required for the formation of odor memories.	REFM 1 Bellen, Taylor, 2001: 98		
ID|FBrf0144501
TP|abstract
|Drosophila meeting abstract
MABST|From an enhancer detection screen for genes expressed preferentially in the
| mushroom bodies, we isolated one line in which the enhancer detector was
| inserted into the first non-coding exon of the fasII gene. fasII encodes
| cell adhesion molecules of the immunoglobulin superfamily.
| Immunohistochemical analysis of Fas II expression confirmed that the
| protein products are concentrated along the axons of the a/ b neurons of
| mushroom bodies. Additional hypomorphic fasII mutants were generated via
| imprecise excision of the enhancer detector. The mutants have normal
| sensory functions (odor avoidance, electric shock avoidance, and odor
| avoidance after electric shock) and normal mushroom body neuron morphology,
| revealed by both light and electron micr oscopic analyses. The fasII rd1
| and fasII rd2 mutants show significantly lower memory than control flies at
| multiple times after olfactory classical conditioning. The performance
| deficit observed immediately after training is fully rescued by inducing a
| hs-fasII transgene with elevated temperature. Furthermore, the rescue of
| early memory can be reversed by switching off the transgene with reduced
| temperature. These experiments argue strongly for a role for Fas II in the
| physiology of mushroom body neurons underlying odor learning. We further
| dissected the role of Fas II by asking whether it serves memory formation,
| memory stability, or memory retrieval. When initial memory performance of
| the mutant is normalized to control animals by over-training, the mut ant
| and control flies exhibit an identical memory decay rate, arguing that
| memory stability is normal in the mutants. Induction of a hs-fasII
| transgene after training but just before testing fails to rescue
| performance, arguing that retrieval functions are not disrupted. These
| results indicate that Fas II is required for memory acquisition, but not
| memory stability or retrieval.
AU|Cheng
|Y.
AU|Endo
|K.
AU|Wu
|K.H.
AU|Davis
|R.
YR|2001
TI|Fasciclin II is required for the formation of odor memories.
JR|Bellen, Taylor, 2001
PG|98
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144502	AU 1 Chern and Choi	YR 1 2001	TP 1 Abstract	TI 1 Lobe is required for domain-specific growth of Drosophila eye disc.	REFM 1 Bellen, Taylor, 2001: 123		
ID|FBrf0144502
TP|abstract
|Drosophila meeting abstract
MABST|Notch (N) activation at the dorsoventral (DV) boundary of the Drosophila eye
| is essential for the growth of the eye. From the DV boundary a growth
| signal is then sent out and interpreted by cells of the dorsal and ventral
| domains. However, the identity of the growth signal and the domain-specific
| effector remain unknown. The Lobe (L) gene is one of the candidate genes
| involved in domain-specific growth. It was first identified in 1925 by
| mutations that preferentially abolish the ventral eye growth. However,
| mechanisms underlying the ventral-specific growth defect is little
| understood. Here we report cloning and characterization of the L gene
| function. L is a novel protein expressed preferentially in undifferentiated
| cells in the eye disc. L is required prior to differentiation to mediate
| the proliferative effect of activated N signaling, and this mediation is
| required only in the ventral domain. Furthermore, L regulates the ventral
| expression of a N ligand, Serrate (Ser), which has a novel function in
| controlling tissue growth. Relations among N, L and Ser may constitute a
| feedback mechanism that regulates N activity. We have also found that loss
| of L causes a ventral-specific, non-autonomous loss of tissue, suggesting
| that L regulates expression of diffusible growth-promoting factor in the
| ventral eye primordium. Together L and Ser present a molecular mechanism
| downstream of N that governs the ventral eye growth independently from
| dorsal eye development.
AU|Chern
|J.
AU|Choi
|K.W.
YR|2001
TI|Lobe is required for domain-specific growth of Drosophila eye disc.
JR|Bellen, Taylor, 2001
PG|123
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144503	AU 1 Cho et al.	YR 1 2001	TP 1 Abstract	TI 1 A model of habituation in Drosophila.	REFM 1 Bellen, Taylor, 2001: 99		
ID|FBrf0144503
TP|abstract
|Drosophila meeting abstract
MABST|Our laboratory has established a method for digitized tracking and anlysis
| of Drosophila movement at a fine resolution. Using this technique we are
| studying the behavioral response of flies to various odors including
| alcohol, an olfactory stimulus abundantly found in the natural environment
| of Drosophila. We have discovered that flies will transiently increase
| locomotor activity within a few seconds of exposure to ethanol vapor.
| Removal of the antennae abolishes this transient hyperlocomotioin. We term
| this olfactory mediated response "startle" as it is an immediate response
| to an olfactory stimulus. With repeated discrete exposures, this startle
| attenuates. This attenuation is reversible by a dishabituating mechanical
| stimulus and is not due to the accumulation of ethanol in the organism. By
| classical criteria, this behavior models habituation, a form of
| nonassociative learning whereby an organism learns to ignore
| inconsequential stimuli. We have modified this behavioral assay for high
| throughput and are screening through a collection of p[ Gal4] enahncer trap
| lines. Several mutants with either decreased or enhanced habituation have
| been identified in this assay. Using this forward genetic approach, we hope
| to discover novel mechanisms of behavioral plasticity in a simple model organism.
AU|Cho
|W.
AU|Wolf
|F.W.
AU|Heberlein
|U.
YR|2001
TI|A model of habituation in Drosophila.
JR|Bellen, Taylor, 2001
PG|99
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144504	AU 1 Choi et al.	YR 1 2001	TP 1 Abstract	TI 1 Electrophysiological and morphological characterization of motorneurons the intact ventral ganglion of third instar Drosophila larvae.	REFM 1 Bellen, Taylor, 2001: 249		
ID|FBrf0144504
TP|abstract
|Drosophila meeting abstract
MABST|To study the properties and modulation of neurons involved in the larval
| neuromuscular system, whole cell patch recordings were performed on ventral
| ganglion neurons. Motorneurons were readily identified with a neuron
| subtype-specific GAL4 line (C164; a gift of Vivian Budnik) driving GFP. The
| neurons studied show stereotypical patterns of activity and morphology that
| allow them to be individually identified within a given hemisegment.
| Concurrent rhodamine fills of specific neurons show that muscle innervation
| by a single neuron is reproducible with regard to the identity of the
| muscle innervated and bouton type. Somatic spikes were recorded from MN6/
| 7-Ib and MNISN-Is (nomenclature of Hoang and Chiba, 2001) neurons under
| current cl amp. The appearance of first spike is significantly delayed and
| the initiation of spike requires larger current amplitude in Is compared to
| Ib cells. Dual recordings at the neuromuscular junction (neuron/ muscle)
| reveal excitatory junction potentials evoked by single neurons. Dual
| recordings within the ventral ganglion (neuron/ neuron) imply a patterned
| circuitry that governs larval movement.
AU|Choi
|J.C.
AU|Park
|D.
AU|Griffith
|L.C.
YR|2001
TI|Electrophysiological and morphological characterization of motorneurons the intact ventral ganglion of third instar Drosophila larvae.
JR|Bellen, Taylor, 2001
PG|249
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144505	AU 1 Chou and Gusella	YR 1 2001	TP 1 Abstract	TI 1 Analysis of a Drosophila homolog of human DYT1 associated with primary torsion dystonia.	REFM 1 Bellen, Taylor, 2001: 183		
ID|FBrf0144505
TP|abstract
|Drosophila meeting abstract
MABST|The primary torsion dystonia is the most severe form of dystonia, a movement
| disorder. A dominant mutation which causes a glutamate codon deletion at
| the 3 prime end of DYT1 gene, mapped to human chromosome 9, has been found
| to account for most cases of the disease. DYT1 encodes torsinA, which
| appears to be a novel member of a protein superfamily of ATPases associated
| with diverse cellular activities (AAA+). A drosophila homolog of DYT1 gene
| has been identified which shows identity of 36% with torsinA along the
| entire region but showing over 70% identity at several functional motifs
| including the walker A and B ATP-binding domains. We have generated a few
| constructs carrying various forms of mutated fly torsin which presumably
| will disrupt normal function in dominant negative manners. The
| overexpression patterns of these constructs in S2 cells as well as eye
| phenotypes in transgenic flies will be discussed. This work will lay the
| foundation to establish a genetic screen to identify genes that potentially
| modify torsinA's effects and thereby to develop effective treatments for dystonia.
AU|Chou
|J.C.
AU|Gusella
|J.
YR|2001
TI|Analysis of a Drosophila homolog of human DYT1 associated with primary torsion dystonia.
JR|Bellen, Taylor, 2001
PG|183
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144506	AU 1 Chow et al.	YR 1 2001	TP 1 Abstract	TI 1 Functional characterization of Drosophila amphiphysin.	REFM 1 Bellen, Taylor, 2001: 23		
ID|FBrf0144506
TP|abstract
|Drosophila meeting abstract
MABST|In vertebrates, amphiphysin (amph) is hypothesized to act as a scaffolding
| protein during synaptic vesicle (SV) endocytosis. However, this model is
| based primarily on in vitro studies. To define the role of amph in vivo, we
| are conducting studies using Drosophila as a model organism. Molecular
| characterization of Drosophila amph reveals multiple isoforms of the
| protein that are highly related at the N-and C-termini. However, consensus
| sequences for binding to other endocytic proteins, such as clathrin, are
| absent. To study amph function in Drosophila, we have taken several
| approaches, including the production of antibodies for biochemical studies,
| and the generation of mutant flies. Using an antibody generated against
| full-length amph, we have found that several amph isoforms are widely
| expressed in diverse tissues throughout development. In embryos, amph is
| localized to epithelial cells and the gut, while in larvae, amph is
| localized to the CNS, imaginal discs and muscle. Immunofluorescent staining
| with pre-and postsynaptic markers at the larval neuromuscular junction
| (NMJ) indicate that amph is postsynaptic. To explore amph function in vivo,
| we have generated mutant flies. Null mutants are viable, but sluggish, and
| show no defects in synaptic morphology or synaptic physiology at the NMJ.
| Amph mutants, however, do demonstrate deficiencies in locomotion compared
| with controls of the same genetic background. These surprising results
| indicate that amph is not required for viability or SV endocytosis at the
| Drosophila larval NMJ. We are currently undertaking several genetic and
| biochemical screens to identify amph interacting proteins. The discovery of
| novel protein partners for amph may reveal functions for amph beyond its
| putative role at the synapse.
AU|Chow
|B.M.
AU|Leventis
|P.A.
AU|Stewart
|B.A.
AU|Boulianne
|G.L.
YR|2001
TI|Functional characterization of Drosophila amphiphysin.
JR|Bellen, Taylor, 2001
PG|23
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144507	AU 1 Chung and Kernan	YR 1 2001	TP 1 Abstract	TI 1 NompA, a ZP-domain extracellular matrix protein, forms part of mechanical linkage between mechanosensory neuron and cuticular structure.	REFM 1 Bellen, Taylor, 2001: 124		
ID|FBrf0144507
TP|abstract
|Drosophila meeting abstract
MABST|Mutations in the no-mechanoreceptor-potential A (nompA) gene disrupt
| mechanosensory transduction in Drosophila. nompA encodes a extracellular
| matrix protein with a ZP domain and several PAN modules; it is expressed
| specifically in each type I sense organ by the support cell that ensheaths
| the neuronal sensory process. Immunostaining and GFP-tagged fusion proteins
| showed that NompA is deposited in the dendrite cap at the apical tip of the
| sensory process. In nompA mutants, the dendrite cap is severely
| disorganized and detached from external cuticular structures and the
| sensory nerve endings. Thus NompA is required in the dendritic cap to
| transmit mechanical stimuli to the transduction apparatus. However, its
| specific role in the cap is still uncertain. To explore this, we have made
| transgenic flies that express various modified NompA proteins in wild type
| and mutant backgrounds. Analyses of these lines will be presented.
AU|Chung
|Y.D.
AU|Kernan
|M.
YR|2001
TI|NompA, a ZP-domain extracellular matrix protein, forms part of mechanical linkage between mechanosensory neuron and cuticular structure.
JR|Bellen, Taylor, 2001
PG|124
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144508	AU 1 Clements et al.	YR 1 2001	TP 1 Abstract	TI 1 Identification of transcriptional targets of eyeless required for neuronal differentiation.	REFM 1 Bellen, Taylor, 2001: 184		
ID|FBrf0144508
TP|abstract
|Drosophila meeting abstract
MABST|The Pax-6 homolog eyeless has been shown to have an essential role in the
| development of the protocerebrum in Drosophila. The gene is expressed in
| the developing and adult optic lobes, mushroom bodies, and central complex.
| The essential role of eyeless in these structures is supported by the brain
| defects observed in recently characterized eyeless mutants. We are focusing
| on the role of eyeless in the mushroom bodies. These neuropiles are
| involved in processing olfactory information and learning and memory. The
| expression of eyeless in mature mushroom body neurons (Kenyon cells), the
| partial or complete loss of these cells in eyeless mutants, and the
| aberrant morphology of the mutant Kenyon cells suggest that eyeless is
| required in mushroom body neuronal differentiation. We hypothesize that
| eyeless regulates a variety of target genes that are required for the
| acquisition and maintenance of neuronal characteristics. We have identified
| several target genes of eyeless whose function is required in postmitotic
| neurons via a genetic screen. In this screen, we analyzed the effects of
| elevated levels of Eyeless protein on reporter gene expression levels. A
| number of these putative target genes have been verified by yeast-1-hybrid
| analysis. We are currently characterizing several of these confirmed target
| genes to better understand their roles in the Drosophila brain and their
| relationship with eyeless.
AU|Clements
|J.
AU|Gafford
|B.
AU|Callaerts
|P.
YR|2001
TI|Identification of transcriptional targets of eyeless required for neuronal differentiation.
JR|Bellen, Taylor, 2001
PG|184
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144509	AU 1 Curtin et al.	YR 1 2001	TP 1 Abstract	TI 1 Gap junction genes are required for the formation of functional chemical synaptic connections in the visual system.	REFM 1 Bellen, Taylor, 2001: 94		
ID|FBrf0144509
TP|abstract
|Drosophila meeting abstract
MABST|Gap junctions have been observed between pre-and post synaptic neurons in
| several experimental systems, but their functional import has never been
| determined. Here, we will present evidence that gap junctions are essential
| precursors for the formation of functional chemical synaptic connections in
| the visual system. Mutants in the Drosophila gap junction ( innexin) genes,
| shakingB ( shB) and optic ganglia reduced (ogre), show defective chemical
| synaptic transmission between the retina and lamina. Both proteins are
| required during pupal development for normal synaptic connections to form.
| Further, ogre is required presynaptically while shB is required
| postsynaptically. This raises the interesting possibility that gap
| junctions form between retina and lamina cells during development as a
| necessary step in formation of functional chemical synapses. Specifically,
| shB and ogre shows reduced/ absent transients in the electroretinalgram
| (ERG). The ERG defect of ogre can be functionally separated from it's
| reduced optic ganglia phenotype. Mosaics in which only the eyes are mutant
| for ogre show this ERG phenotype. In addition, ogre ERGs can be rescued by
| driving ogre expression with sev-Gal4 and elav-Gal4 without rescuing the
| optic ganglia phenotype. These experiments also show that ogre is requi red
| in photoreceptors for normal ERGs. ShB's ERG defect is rescued by driving
| shB( N) expression via elav-Gal4 driver, but not a sev-Gal4 or GMR-Gal4,
| suggesting that shB( N) is required in the lamina. It may also be required
| in the retina. Both proteins are expressed in the visual system during the
| first half of pupal development when chemical synapses form. Both also need
| to be expressed during pupal development for rescue. Lasly, both mutants
| lead to minor errors in axonal projections of R1-8. For shB these defects
| are seen only in a minority of animals and for the most part pathfinding is
| normal in shB. These defects are more noticeable in ogre mutant eye animals.
AU|Curtin
|K.D.
AU|Zhang
|Z.
AU|Wyman
|R.J.
YR|2001
TI|Gap junction genes are required for the formation of functional chemical synaptic connections in the visual system.
JR|Bellen, Taylor, 2001
PG|94
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144510	AU 1 Curtin et al.	YR 1 2001	TP 1 Abstract	TI 1 Gap junction genes are not created equal: Mapping protein regions needed to promote functional chemical synaptic connections in visual system.	REFM 1 Bellen, Taylor, 2001: 24		
ID|FBrf0144510
TP|abstract
|Drosophila meeting abstract
MABST|Temporary gap junctions (GJs) have been observed between pre-and
| post-synaptic neurons. Recently, we showed that GJs are a necessary
| precursor to the formation of functional chemcial synatic connections in
| the Drosophila visual system. Mutations in two Drosophila GJ genes
| (innexins), shakingB (shB) and optic ganglia reduced (ogre), lead to a loss
| of transients in the electroretinogram (ERG) indicative of synaptic failure
| between the retina and lamina. Ogre is required presynaptically and shB( N)
| postsynaptically. Both act during development. Innexins are a large family.
| However, despite their high sequence homology, functional differences have
| been reported. Some form homotypic GJs while others do not. Others form
| heteromeric junctions. Voltage gating properties also vary. The biological
| implications of innexin differences have not been explored. Here we ask if
| innexins are interchangeable in promoting functional chemical synapses in
| flies. Specifically, we tested several innexins for their ability to rescue
| shB and ogre mutant ERGs and found that, by and large, innexins are not
| interchangeable. We mapped the protein regions required for this
| specificity by making chimeras between shB( N) and ogre and testing their
| ability to rescue both mutants. Each chimera rescued either shB or ogre,
| but never both. Specificity in GJ formation or function could contribute to
| chemical synaptic specificity by regulating which neurons couple and what
| signals they exchange. Cells may couple only if their innexins can mate
| with each other. The partially overlapping expression patterns of several
| innexins make this "mix and match" model of GJ formation a possibility.
AU|Curtin
|K.D.
AU|Zhang
|Z.
AU|Wyman
|R.J.
YR|2001
TI|Gap junction genes are not created equal: Mapping protein regions needed to promote functional chemical synaptic connections in visual system.
JR|Bellen, Taylor, 2001
PG|24
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144511	AU 1 Dauwalder et al.	YR 1 2001	TP 1 Abstract	TI 1 The takeout gene is controlled by the sex determination pathway and interacts with Fru in male courtship.	REFM 1 Bellen, Taylor, 2001: 100		
ID|FBrf0144511
TP|abstract
|Drosophila meeting abstract
MABST|Sex determination is controlled by a hierarchy of regulatory genes
| culminating with the sex-specific transcription factors doublesex and
| fruitless. These terminal factors are believed to regulate the sex-specific
| expression of numerous target genes that participate in sexual
| differentiation and sex-specific behavior. However, few of these target
| genes have yet been identified. In a subtractive hybridization screen
| directed at identifying sex-specific genes expressed in fly heads we
| identified several novel male-specific transcripts. One of the transcripts
| identified derives from the takeout gene, a factor concurrently identified
| as a circadian-regulated factor involved in the starvation response.
| Sequence comparisons reveal that takeout defines a novel gene family with
| at least twenty different members in the Drosophila genome. The proteins in
| this family seem to be secreted and to have limited similarity to factors
| known to bind lipophiles. We find that under non-starvation conditions
| takeout is expressed almost exclusively in the fat bodies of male heads and
| in subsets of cells in the antennae and the maxillary palp. Expression of
| takeout is under the control of the sex-determination pathway as shown by
| its activation in tra-2 mutant diplo-X individuals. In males, both dsx and
| fru activate expression of takeout, whereas in females dsx is involved in
| repressing the gene. Expression of the female-specific TRA protein under
| the control of the takeout promoter reduces the courtship index in male
| flies, demonstrating that the male identity of takeout expressing cells is
| important for normal courtship behavior. Furthermore, fru heterozygous
| males which are mutant for takeout show a reduction in courtship,
| suggesting that takeout interacts with the fru pathway in male courtship.
AU|Dauwalder
|B.
AU|Tsujimoto
|S.
AU|Moss
|J.
AU|Mattox
|W.
YR|2001
TI|The takeout gene is controlled by the sex determination pathway and interacts with Fru in male courtship.
JR|Bellen, Taylor, 2001
PG|100
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144512	AU 1 Yu et al.	YR 1 2001	TP 1 Abstract	TI 1 Transgenically-supplied fluorescent indicators of the physiological responses of neurons in the Drosophila brain.	REFM 1 Bellen, Taylor, 2001: 82		
ID|FBrf0144512
TP|abstract
|Drosophila meeting abstract
MABST|The learning of odors and the expression of odor memories requires the
| participation of mushroom body neurons. Despite the identification of the
| relevant neurons along with a handful of required genes and proteins, there
| remains no readily available method for monitoring the physiological state
| of these neurons. Such methodology is critical in order to understand the
| changes in neuronal physiology that occur with the formation,
| consolida-tion, and expression of odor memories. We have developed several
| UAS-transgenes that encode protein fusions of GFP with potential for
| monitor-ing in vivo changes in calcium level, membrane potential, and
| synaptic activity. These have been expressed in all mushroom body neurons
| or in selected sets of mushroom body neurons using the GAL4 system. Calcium
| responses of mushroom body neurons to ionic depolarization or stimulation
| with neurotransmitters have been monitored with camgaroos, which are
| insertions of calmodulin inside yellow mutants of GFP (Baird et al, PNAS
| 96: 11241-6, 1999; Griesbeck et al, J. Biol. Chem. in press, 2001).
| Camgaroos increase fluorescence acutely in response to elevations of
| calcium or pH. Strong depolarization with K + leads to a robust but
| transient increase in fluorescence of two different camgaroos. This
| response is not due to a change in intracellular pH from depolar-ization,
| since intracellular pH indicators reported a slight decrease in pH with
| depolarization. Fluorescence increases were attenuated by calcium channel
| blockers or by chelating extracellular calcium, indicating that the
| responses are due to calcium influx through voltage-dependent calcium
| channels. Acetylcholine (ACh) is the putative neurotransmitter released by
| antennal lobe relay neurons onto the dendrites of mushroom body neurons in
| the calyx. Application of ACh to the calyx produced a rapid and tran s-ient
| increase in fluorescence in the axons of mushroom body neurons but not in
| the cell bodies or dendrites. In addition, the calcium increases occurred
| in all three classes of mushroom body neurons, including the a/ b, a'/ b',
| and g neurons, showing that all mushroom body neurons respond to ACh
| stimulation. These increases were blocked with antagonists of nicotinic ACh
| receptors. Thus, all mushroom body neurons respond to ACh stimulation with
| activation of voltage-dependent calcium channels distributed along their
| axons. The validation of this system and establish-ment of these baseline
| properties now offer the possibility of monitoring in vivo in both normal
| or mutant animals, the changes in neuronal calcium that occur during
| behavioral conditioning, the administration of drugs, or the presentation
| of other types of environmental stimuli.
AU|Yu
|D.
AU|Baird
|G.S.
AU|Tsien
|R.Y.
AU|Davis
|R.L.
YR|2001
TI|Transgenically-supplied fluorescent indicators of the physiological responses of neurons in the Drosophila brain.
JR|Bellen, Taylor, 2001
PG|82
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144513	AU 1 Dean and Booker	YR 1 2001	TP 1 Abstract	TI 1 The role of dTRAFs 1 and 2 in Drosophila development.	REFM 1 Bellen, Taylor, 2001: 150		
ID|FBrf0144513
TP|abstract
|Drosophila meeting abstract
MABST|TRAFs (tumor necrosis factor receptor-associated factors) are important
| mediator proteins in the TNF/ NGF pathways. Through a conserved domain,
| these molecules bind to TNF/ NGF receptor complexes and act as adaptors,
| recruiting downstream pathways to the receptor by physically coupling them.
| Here, we describe the isolation and characterization of mutations in dtrafs
| 1 and 2 of Drosophila. Our results suggest a role for dtraf1 in larval
| growth and for dtraf2 in early embryogenesis.
AU|Dean
|D.M.
AU|Booker
|R.
YR|2001
TI|The role of dTRAFs 1 and 2 in Drosophila development.
JR|Bellen, Taylor, 2001
PG|150
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144514	AU 1 Rao et al.	YR 1 2001	TP 1 Abstract	TI 1 Neuropeptides affect an extremely diverse set of physiological processes.	REFM 1 Bellen, Taylor, 2001: 25		
ID|FBrf0144514
TP|abstract
|Drosophila meeting abstract
MABST|Neuropeptides affect an extremely diverse set of physiological processes.
| Neuropeptides are often coreleased with neurotransmitters and, unlike
| neurotransmitters, cells responding to neuropeptides may be distant from
| the site of secretion. Thus, it is often difficult to measure the amount of
| neuropeptide release in vivo by electrophysiological methods. Here we
| report the development of an in vivo system for studying the developmental
| expression, processing, transport, and release of neuropeptides. A
| GFP-tagged atrial natruiretic factor fusion (preproANF-EMD) was expressed
| in the Drosophila nervous system with the panneural promoter, elav. During
| embryonic development, proANF-EMD was first seen to accumulate in synaptic
| regions of the CNS in stage 17 embryos. By the third instar larval stage,
| highly fluorescent neurons were evident throughout the CNS and PNS. In the
| adult, fluorescence was pronounced in the mushroom bodies, antennal lobe,
| and the central complex. At the larval neuromuscular junction, proANF-EMD
| was concentrated in nerve terminals. We compared the release of proANF-EMD
| from synaptic boutons of NMJ 6/ 7 which contain almost exclusively
| glutamate containing clear vesicles to those of NMJ 12 which include the
| peptidergic type III boutons. Upon depolarization, approximately 60% of the
| tagged neuropeptide was released from NMJs of both muscles in 15 minutes.
| Although the elav promoter is uniformly active in the Drosophila nervous
| system, NMJ 12, prior to stimulation, contained on average 46-fold more
| neuropeptide than did NMJ 6/ 7, and thus, NMJ 12 released much more
| proANF-EMD during stimulation. Our results suggest that peptidergic neurons
| have an enhanced ability to accumulate neuropeptides as compared to neurons
| that primarily release classical neurotransmitters.
AU|Rao
|S.
AU|Lang
|C.
AU|Levitan
|E.S.
AU|Deitcher
|D.L.
YR|2001
TI|Neuropeptides affect an extremely diverse set of physiological processes.
JR|Bellen, Taylor, 2001
PG|25
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144515	AU 1 Demidenko et al.	YR 1 2001	TP 1 Abstract	TI 1 Regulated nuclear export of the homeodomain transcription factor Prospero.	REFM 1 Bellen, Taylor, 2001: 151		
ID|FBrf0144515
TP|abstract
|Drosophila meeting abstract
MABST|Subcellular distribution of the Prospero protein is dynamically regulated
| during Drosophila nervous system development. Prospero is first detected in
| neuroblasts where it becomes cortically localized and tethered by the
| adapter protein, Miranda. After division, Prospero enters the nucleus of
| daughter ganglion mother cells where it functions as a tr anscription
| factor. We have identified a novel Prospero allele, which produces a
| protein lacking the C-terminal 30 amino acids of the highly conserved
| Prospero domain. This results in the protein remaining in the cytoplasm of
| ganglion mother cells. Molecular dissection of the homeo -and Prospero
| domains, and expression of chimeric Prospero proteins in mammalian and
| insect cells indicates that Prospero contains a nuclear export signal that
| is masked by the Prospero domain. Nuclear export signal of Prospero, which
| is sensitive to the drug Leptomycin B, is mediated by Exportin.
| Site-directed mutagenesis shows that the conserved hydrophobic residues of
| the Prospero nuclear export signal Leu1252, Leu1257, Leu1262 or Phe1264 are
| essential for its export activity, and the tertiary structure of Prospero
| may regulate its export. Mutation of the nuclear export signal-mask in
| Drosophila embryos prevents Prospero nuclear localization in ganglion
| mother cells. We propose that a combination of cortical tethering and
| regulated nuclear export controls Prospero subcellular distribution and
| function in all higher eukaryotes.
AU|Demidenko
|Z.N.
AU|Badenhorst
|P.
AU|Jones
|T.
AU|Bi
|X.
AU|Mortin
|M.A.
YR|2001
TI|Regulated nuclear export of the homeodomain transcription factor Prospero.
JR|Bellen, Taylor, 2001
PG|151
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144516	AU 1 Desai	YR 1 2001	TP 1 Abstract	TI 1 Neural RPTPs may form inhibitory heterodimers.	REFM 1 Bellen, Taylor, 2001: 208		
ID|FBrf0144516
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila, at least five RPTPs are highly expressed by neurons and
| function to help developing CNS, motor and/ or retinal axons reach their
| synaptic targets. Genetic analysis reveals that two of these RPTPs, DLAR
| and PTP99A function antagonistically at a specific axonal choice point. The
| ISNb nerve bypasses its ventrolateral muscle (VLM) targets in Dlar mutants
| but innervates the VLM in Dlar: Ptp99A double mutants, indicating that DLAR
| normally functions to inhibit or counteract PTP99A during ISNb axon
| outgrowth. Experiments involving the structure and function of the
| cytoplasmic domains of vertebrate RPTPs suggest that some RPTPs may form
| inhibitory homodimers. Although inhibitory heterodimer formation between
| DLAR and PTP99A is an attractive model to explain these genetic results,
| neither hetero-nor homodimer formation have been directly detected in
| Drosophila. Here we report the identification of a novel Ptp69D mutant
| whose phenotypes can also be explained by the formation of inhibitory RPTP
| heterodimers. Ptp69D 7A2 homozygote embryos have a much more severe
| phenotype than that of Ptp69D( �) null embryos. The motor axon defects
| conferred by Ptp69D 7A2 phenocopy those seen in Dlar, Ptp69D double mutants
| whereas the CNS defects are similar to those seen in Ptp10D; Ptp69D double
| mutants. Furthermore, these defects are dose-dependent, with the phenotype
| of Ptp69D 7A2 > Ptp69D 7A2 /Ptp69D( �) > Ptp69D( �). These results
| suggest that the protein encoded by Ptp69D 7A2 poisons both DLAR and
| PTP10D. Both motor and central axon defects can be suppressed by increasing
| the expression of PTP99A and enhanced by reducing the expression of PTP10D.
| These results are consistent with the interpretation that PTP69D 7A2
| interacts directly with DLAR, PTP10D and PTP99A and that this interaction
| inactivates DLAR and PTP10D.
AU|Desai
|C.
YR|2001
TI|Neural RPTPs may form inhibitory heterodimers.
JR|Bellen, Taylor, 2001
PG|208
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144517	AU 1 Deshpande and Urban	YR 1 2001	TP 1 Abstract	TI 1 The role of yan in the development of the embryonic CNS.	REFM 1 Bellen, Taylor, 2001: 152		
ID|FBrf0144517
TP|abstract
|Drosophila meeting abstract
MABST|Different cell types in the Drosophila central nervous system (CNS) are
| formed from a relatively few precursor cells, the neuroblasts (NBs), which
| delaminate from the neurogenic region of the ectoderm. The delamination
| occurs in five waves, S1-S5, finally leading to a subepidermal layer
| consisting of about 30 NBs, each with a unique identity, arranged in a
| stereotyped spatial pattern in each hemisegment. This information depends
| on several factors such as the concentrations of various morphogens,
| cell-cell interactions and long range signals present at the position and
| time of its birth. The early NBs, delaminating during S1 and S2, form an
| orthogonal array of four rows (2/ 3,4,5,6/ 7) and three columns (medial,
| intermediate, and lateral). However, the three column and four
| row-arrangement pattern is only transitory during early stages of
| neurogenesis which is obscured by late emerging (S3-S5) neuroblasts.
| Therefore the aim of our study has been to identify novel genes which play
| a role in the formation or specification of late delaminating NBs. A
| genetic screen in collaboration with the Dr. C Kl�mbt was done to identity
| novel and yet unidentified genes in the process of late neuroblast
| formation and specification. We found NB 7-3, a late delaminating
| neuroblast, to be missing in one of the mutant stocks which was later found
| to localise on the gene anterior open or yan. This gene encodes a
| transcription factor that functions as a negative regulator of cell
| differentiation and proliferation. Here we present data regarding the role
| of yan in context to the Notch signalling pathway in CNS development, as we
| find that the embryonic mutant phenotype of Notch is suppressed by the yan
| mutation. Further, ectopic expression of activated Yan in the neuroectoderm
| mimics a neurogenic phenotype. The cause of this neurogenic phenotype seems
| to due to the down regulation of the expression of the Notch target,
| Enhancer of split (E( spl)). Thus, we hypothesise that yan is responsible
| for maintaining the cells of the neuroectoderm in an undifferentiated state
| by counter acting the Notch signal thereby promoting neural fate.
AU|Deshpande
|N.
AU|Urban
|J.
YR|2001
TI|The role of yan in the development of the embryonic CNS.
JR|Bellen, Taylor, 2001
PG|152
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144518	AU 1 Dobritsa et al.	YR 1 2001	TP 1 Abstract	TI 1 The steroidogenic gene dare plays roles in nervous system development, maintenance and function.	REFM 1 Bellen, Taylor, 2001: 125		
ID|FBrf0144518
TP|abstract
|Drosophila meeting abstract
MABST|Steroid hormones play important roles in the development and function of the
| nervous system in both invertebrates and vertebrates. Little is known about
| the source of steroids that participate in these processes. An interesting
| possibility is that steroid hormones are synthesized within the brain and
| act locally to modulate nervous system functions. The Drosophila mutant
| dare has defects in steroid synthesis, as well as in the maturation and
| function of the nervous system. Cloning of the dare gene reveal ed that it
| encodes a homologue of the mammalian enzyme adrenodoxin reductase, which is
| required for the biosynthesis of steroid hormones. An allelic series has
| been generated for dare, and the resulting alleles have a variety of
| phenotypes. The hypomorphic dare 1 mutant, which contains a P element
| insertion, has abnormal responses to olfactory and visual stimuli. Null
| alleles have molting defects and undergo second instar lethality.
| Intermediate allelic combinations show a delay of pupariation, severe
| uncoordination, and significant and widespread degeneration of the adult
| nervous system, suggesting that dare in required to maintain the integrity
| of the nervous system. All of the defects are fully rescued by a transgenic
| copy of dare. At least some of the abnormalities of dare mutants, such as
| defects in molting and pupariation, can be rescued by feeding mutants the
| insect steroid hormone ecdysone, thus providing evidence that the
| production of steroids is in fact affected in dare. Overexpression of dare
| within the nervous system (in all or particular subsets of neurons, but not
| in glia) rescues dare-induced neurodegeneration but does not have an effect
| on other mutant phenotypes, such as defects in female fertility, thus
| suggesting the possibility that steroids can be produced and can function
| locally within the nervous system of Drosophila. To see if dare is involved
| in the development of the nervous system, and also to examine the autonomy
| of dare function, we performed mosaic analysis of the fly eyes. We found
| that dare is indeed required for eye development and that it functions
| there in a cell-autonomous manner.
AU|Dobritsa
|A.A.
AU|Freeman
|M.R.
AU|Carlson
|J.R.
YR|2001
TI|The steroidogenic gene dare plays roles in nervous system development, maintenance and function.
JR|Bellen, Taylor, 2001
PG|125
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144519	AU 1 Dobritsa et al.	YR 1 2001	TP 1 Abstract	TI 1 Odor receptor expression and olfactory coding in Drosophila.	REFM 1 Bellen, Taylor, 2001: 7		
ID|FBrf0144519
TP|abstract
|Drosophila meeting abstract
MABST|A family of candidate odorant receptor (DOR) genes has recently been
| identified in Drosophila. It includes about 60 members predicted to encode
| G-protein coupled receptors. DOR genes are expressed in neurons of two
| olfactory organs: the third antennal segment and the maxillary palp. A
| major problem in this system is to determine the functional organization of
| receptor gene expression. How does the expression of individual receptors
| among the neurons of the olfactory system, as determined by molecular
| means, correlate with the electrophysiological responses of these neurons
| to individual odors? Odorant receptors are expected to localize to the
| dendrites of olfactory receptor neurons (ORNs). To determine the
| subcellular localization of DOR proteins, we raised an antibody predicted
| to recognize two closely related family members expressed in the antenna,
| DOR 22a and 22b. Immunofluorescence labeling shows that these proteins are
| localized within a subset of olfactory sensilla on antenna, exactly as
| expected for an odorant receptor expressed in the dendrites. ImmunoEM
| analysis confirmed that the antibody indeed labels the dendritic membrane.
| The sensilla stained with the antibody belong to a particular morphological
| class, the large sensilla basiconica. There are three physiologically
| distinct subtypes among this class, known as ab1, ab2, and ab3. To find out
| in which physiological subtype the DOR 22a gene is expressed, we have
| created a line expressing GAL4 under the control of the DOR 22a promoter.
| When this line is crossed with the UAS-GFP reporter line, GFP fluorescence
| is found in the subset of sensilla corresponding to those in which the
| endogenous DOR 22a gene is expressed. We performed electrophysiological
| single-unit recordings on the GFP -labelled sensilla, and determined that
| all 22a-expressing sensilla belong to the physiological class ab3. To find
| out in which of the two ORNs in the ab3 sensilla the 22a receptor is
| present, we are killing or inactivating the DOR 22a-expressing neurons. We
| have also linked expression of another gene, DOR 85e, to a particular
| functional type of ORNs. This gene is expressed in the maxillary palps, and
| using similar kind of analysis we found that it is expressed in the pb1A
| ORNs, which respond strongly to ethyl acetate. A maxillary palp contains
| only 6 functional types of ORNs, and thus this approach should enable us to
| construct an integrated molecular and physiological map for this olfactory organ.
AU|Dobritsa
|A.A.
AU|Warr
|C.G.
AU|van der Goes van Naters
|W.
AU|Steinbrecht
|R.A.
AU|Carlson
|J.R.
YR|2001
TI|Odor receptor expression and olfactory coding in Drosophila.
JR|Bellen, Taylor, 2001
PG|7
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144520	AU 1 Drier et al.	YR 1 2001	TP 1 Abstract	TI 1 Memory enhancement by a mammalian atypical PKC isoform, PKMz in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 101		
ID|FBrf0144520
TP|abstract
|Drosophila meeting abstract
MABST|Synaptic stimulation can activate signal-transduction pathways, producing
| persistently active protein kinases, and these have been attractive
| candidate components of memory mechanisms. PKMz is a truncated,
| persistently activated isoform of an atypical protein kinase C (aPKCz),
| which lacks the N-terminal pseudosubstrate regulatory domain. We used a
| Pavlovian olfactory learning paradigm in Drosophila to examine the role of
| PKMz in memory formation. We find that induction of the mouse PKMz (MaPKMz)
| transgene enhances memory. This enhancement requires persistent kinase
| activity, since induction of neither a full-length nor a kinase-dead
| transgene produces this effect. The MaPKMz-mediated enhancement is
| temporally specific: it is optimal if the transgene is induced 30 minutes
| after training and does not occur if induced prior to, or more than 2 hours
| post-training. An atypical PKC has been identified in Drosophila, and
| Western blots as well a s kinase activity assays indicate that the M-form
| of this kinase is present and active in Drosophila heads. As with the mouse
| homologue, induction of a transgene encoding the putative M-form of the
| Drosophila aPKC also enhances memory. We also find that both chelerythrine,
| an inhibitor of PKM activity, and induction of a dominant-negative MaPKMz
| transgene inhibit memory without affecting learning. Thus, aPKM is
| necessary for normal memory maintenance and is sufficient to enhance this
| process. The temporal specificity leads us to speculate that aPKM is part
| of, or is acted upon, by the synaptic tag.
AU|Drier
|E.A.
AU|Cowan
|M.
AU|Tello
|M.K.
AU|Wu
|P.
AU|Blace
|N.
AU|Sacktor
|T.C.
AU|Yin
|J.C.P.
YR|2001
TI|Memory enhancement by a mammalian atypical PKC isoform, PKMz in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|101
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144521	AU 1 Dubnau and Tully	YR 1 2001	TP 1 Abstract	TI 1 Functional anatomy of olfactory memory: Dissection of spatial and temporal requirements for neurotransmission during memory consolidation.	REFM 1 Bellen, Taylor, 2001: 102		
ID|FBrf0144521
TP|abstract
|Drosophila meeting abstract
MABST|Lesion experiments usually result in irreversible brain damage, which has
| limited their use for dissecting the temporally and mechanistically
| distinct processes of acquisition, storage and memory retrieval. By using a
| Gal4 driven temperature -sensitive shibire transgene to disrupt synaptic
| transmission reversibly and on the time-scale of minutes, we have
| investigated the temporal and spatial requirements for ongoing neural
| activity during memory formation. By transiently disrupting synaptic
| activity in several relevant anatomical loci, we demonstrate distinct
| temporal and spatial requirements for synaptic transmission during
| acquisition, consolidation and retrieval of olfactory memory.
AU|Dubnau
|J.
AU|Tully
|T.
YR|2001
TI|Functional anatomy of olfactory memory: Dissection of spatial and temporal requirements for neurotransmission during memory consolidation.
JR|Bellen, Taylor, 2001
PG|102
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144522	AU 1 Caldwell et al.	YR 1 2001	TP 1 Abstract	TI 1 Effects of chordotonal mutants on larval locomotion.	REFM 1 Bellen, Taylor, 2001: 126		
ID|FBrf0144522
TP|abstract
|Drosophila meeting abstract
MABST|Chordotonal organs (CHO) underlie hearing and proprioception in the
| Drosophila adult. Mutations that disrupt adult CHO function are likely to
| affect larval CHOs as well; in fact one CHO mutant, touch-insensitive larva
| B (tilB), was first identified by larval insensitivity to touch. We have
| found that other CHO mutants are similarly touch-insensitive, including
| atonal (ato), beethoven (btv), smetana (smet) and 5D10. We wanted determine
| whether larval CHO function may provide sensory feedback during locomotion.
| By staining CHO mutants with monoclonal antibody 22C10 (pan-neural) we
| documented morphological defects in number, position and orientation in the
| lateral pentascolopidial organs of the larval abdominal segments. Using
| DIAS (Dynamic Image Analysis System) software, we next analyzed larval
| locomotor patterns. This software tracks, frame-by-frame, the paths taken
| by third instar wandering larvae in parameters such as speed, acceleration
| and direction change. This analysis has shown severe defects in larval
| paths in CHO mutants as compared to the wild type. Furthermore, there are
| statistically significant differences between mutant and wild-type strains
| for speed and for direction change, but not for acceleration. Overall, we
| are able to demonstrate that CHO dysfunction is associated with aberrant
| larval locomotion.
AU|Caldwell
|J.C.
AU|Miller
|M.M.
AU|Wing
|S.
AU|Eberl
|D.F.
YR|2001
TI|Effects of chordotonal mutants on larval locomotion.
JR|Bellen, Taylor, 2001
PG|126
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144523	AU 1 Elmore and Smith	YR 1 2001	TP 1 Abstract	TI 1 Subcellular localization and developmental expression of putative odor receptor OR43b.	REFM 1 Bellen, Taylor, 2001: 127		
ID|FBrf0144523
TP|abstract
|Drosophila meeting abstract
MABST|Two families of putative odor receptors have been identified in Drosophila.
| Members of these families are expressed in subsets of olfactory neurons,
| consistent with a role in odorant transduction, although receptor function
| has not yet been demonstrated. To gain insight into the role of this family
| in olfactory transduction and axonal guidance I have analyzed the cellular
| and subcellular localization of a member of this family, OR43b. This
| receptor is expressed in approximately 15 neurons of the third antennal
| segment. The protein is concentrated in the dendrites; the site of odor
| transduction. To explore the possibility that these receptors mediate
| axonal guidance, I undertook a developmental time course study. Receptor
| protein is first detected late in pupal development, long after olfactory
| neurons enter the antennal lobe. These findings suggest that OR43b may
| mediate odor responses but unlike the odorant receptors in vertebrates,
| this receptor probably does not play a role in neuronal pathfinding.
AU|Elmore
|T.
AU|Smith
|D.
YR|2001
TI|Subcellular localization and developmental expression of putative odor receptor OR43b.
JR|Bellen, Taylor, 2001
PG|127
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144524	AU 1 Emerson and Van Vactor	YR 1 2001	TP 1 Abstract	TI 1 A misexpression/overexpression screen for genes regulating embryonic motoneuron axon guidance.	REFM 1 Bellen, Taylor, 2001: 65		
ID|FBrf0144524
TP|abstract
|Drosophila meeting abstract
MABST|We are interested in understanding the molecular mechanisms that control
| axon guidance decisions.. We have chosen to employ the misexpression/
| overexpression strategy developed by P. Rorth as well as higher resolution
| microscopy than used in past screens to this end. This combination allows
| for the identification of relevent molecules missed in previous screens due
| to low penetrance, loss-of-function phenotypes or due to the low power
| screening procedure used. We have screened ~600 lines for embryonic
| motoneuron axon guidance phenotypes caused by misexpression of genes in
| mesoderm with the pan-medodermal Gal4 driver 24B and/ or neurons with the
| postmitotic driver elav-Gal4 using the FasII antibody to visualize axons.
| We identified three broad categories of mutations -those affecting the
| architecture of the CNS, those causing muscle abnormalities, and those with
| motoneuron phenotypes. We have focused on the four genes that have specific
| motoneuron phenotypes. Two of these genes have expression in a subset of
| CNS cells and have not been identified previously. Our studies have focused
| on identifying loss-of-function phenotypes for these same genes and the
| signalling pathways associated with them.
AU|Emerson
|M.M.
AU|Van Vactor
|D.
YR|2001
TI|A misexpression/overexpression screen for genes regulating embryonic motoneuron axon guidance.
JR|Bellen, Taylor, 2001
PG|65
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144525	AU 1 Ewer et al.	YR 1 2001	TP 1 Abstract	TI 1 Neuroendocrine and circadian control of ecdysis behavior.	REFM 1 Bellen, Taylor, 2001: 177		
ID|FBrf0144525
TP|abstract
|Drosophila meeting abstract
MABST|Insect growth and development occurs through multiple stages. Each stage
| culminates with ecdysis, the shedding of the remaining cuticle from the
| previous stage. Most of what is known about the neuroendocrine control of
| ecdysis behavior stems from research done in the hornworm, Manduca sexta.
| In this moth, the neuropeptide Crustacean Cardioactive Peptide (CCAP)
| appears to be the key peptide that turns on ecdysis behavior. We have
| examined the in vivo role of CCAP by creating CCAP-GAL4 transgenes and
| selectively ablating the CCAP neurons by driving rpr expression. Larvae
| completely lacking CCAP neurons display seemingly normal larval ecdysis
| behavior, but invariably die at pupation. These results suggest that CCAP
| is not essential for larval ecdysis in Drosophila. This is consistent with
| our findings in other dipteran species, and implies that the model derived
| from Manduca needs to be reinterpreted. Escaper adults with a targeted
| ablation of CCAP neurons show defects in cuticle tanning and wing
| inflation, suggesting that CCAP neurons may also be involved in the control
| of these post-ecdysial events. In Drosophila, adult ecdysis (eclosion) is
| regulated by the circadian clock, such that emergence occurs mostly during
| the early part of the subjective day. Mutations in lark advance the timing
| of eclosion. LARK shows a circadian rhythm of abundance in CCAP neurons,
| suggesting that these neurons may also provide circadian timing to adult
| eclosion. Yet, preliminary evidence suggests that adults lacking CCAP
| neurons exhibit normal eclosion rhythms. Nevertheless, the overexpression
| of LARK in CCAP neurons causes a phase shift in the timing of eclosion.
| These results and others suggest that at least 2 distinct modulatory
| pathways contribute to the clock control of eclosion.
AU|Ewer
|J.
AU|del Campo
|M.
AU|Park
|J.
AU|Schroeder
|A.J.
AU|Kume
|K.
AU|Akten
|B.
AU|Jackson
|F.R.
YR|2001
TI|Neuroendocrine and circadian control of ecdysis behavior.
JR|Bellen, Taylor, 2001
PG|177
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144526	AU 1 Faivre-Sarrailh et al.	YR 1 2001	TP 1 Abstract	TI 1 Drosophila F3/Contactin is required in axonal insulation.	REFM 1 Bellen, Taylor, 2001: 209		
ID|FBrf0144526
TP|abstract
|Drosophila meeting abstract
MABST|We cloned the Drosophila homologue of vertebrate F3/ Contactin, which
| interacts with Neurexin IV (NRX IV) to study its role in axonal insulation.
| In vertebrates, F3/ Contacti n is a GPI-anchored cell adhesion molecule of
| the immunoglobulin (Ig) superfamily implicated in multiple events during
| brain development such as axonogenesis and myelination. In particular, it
| binds L1-molecules, related to Drosophila Neuroglian (NRG) and NCP1/ Caspr/
| Paranodin, related to NRX IV. These proteins play a highly conserved
| function in the formation of septate junctions and axonal insulation across
| species (Bellen et al., 1998, TINS 21: 444). Drosophila Contactin (DCONT)
| displays a 30% sequence identity, and shows modular organization similar to
| vertebrate F3/ Contactin. These domains include 6 Ig domains and 4 FNIII
| repeats. In addition, DCONT contains an N-terminal C-lectin domain.
| Immunohistochemical analysis in the embryos revealed that DCONT is
| coexpressed with NRX IV and NRG in all epithelial cells derived from the
| ectoderm. NRX IV is component of pleated septate junctions and displays an
| apicolateral distribution in epithelial cells. As expected for a
| GPI-anchored molecule, DCONT also displays an apical distribution. In nrx
| IV null mutants, DCONT localization becomes nonpolarized indicating that
| NRX IV is required for the proper subcellular localization of DCONT. DCONT
| expression coincides with that of NRX IV and NRG in glial cells of the PNS,
| which have been shown to contain septate junctions and are required for
| blood-nerve barrier formation. DCONT does not seem to be expressed in the
| brain or ventral nerve cord. Coimmunoprecipitation experiments using
| embryonic lysates indicate that DCONT interacts with NRX IV but not with
| NRG. Genetic and biochemical experiments are underway to determine the
| precise role of DCONT in axonal insulation and /or blood-nerve barrier
| formation during embryonic development.
AU|Faivre-Sarrailh
|C.
AU|Nicolas
|S.
AU|Li
|J.
AU|Hortsch
|M.
AU|Bhat
|M.A.
YR|2001
TI|Drosophila F3/Contactin is required in axonal insulation.
JR|Bellen, Taylor, 2001
PG|209
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144527	AU 1 Feathersone et al.	YR 1 2001	TP 1 Abstract	TI 1 Bad reception (brec) is essential for glutamate receptor field formation.	REFM 1 Bellen, Taylor, 2001: 26		
ID|FBrf0144527
TP|abstract
|Drosophila meeting abstract
MABST|We have isolated EMS mutants in a gene we call bad reception (brec). The
| gross morphology of brec mutants is normal, with no defects in cuticle
| formation, gut, CNS, muscle shape, muscle patterning, or body wall
| innervation visible by light microscopy. brec mutants are, however,
| completely paralyzed and thus die as embryos. Electrophysiological and
| immunohistochemical analysis shows that brec mutant NMJs are completely
| devoid of glutamate receptors, despite normal morphology and the presence
| of other synaptic proteins. RT-PCR shows that glutamate receptor subunit
| mRNA is normally abundant in brec homozygotes, and brec homozygotes do not
| express glutamate receptors even if multiple copies of glutamate receptor
| subunits (glurIIA/ B) are driven by a strong muscle promoter (MHC).
| MHC-driven expression of glurIIA/ B normally results in gross
| overexpression and mislocalization of receptors, and can rescue glurIIA+
| glurIIB deletions to viability. Based on our results, we conclude that brec
| is essential for translational or post -translational expression of
| glutamate receptors at the Drosophila NMJ.
AU|Feathersone
|D.E.
AU|Rushton
|E.
AU|Broadie
|K.
YR|2001
TI|Bad reception (brec) is essential for glutamate receptor field formation.
JR|Bellen, Taylor, 2001
PG|26
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144528	AU 1 Fergestad et al.	YR 1 2001	TP 1 Abstract	TI 1 mind the gap (MTG) encodes a prolyl-4-hydroxylase a-like enzyme required for glutamate receptor field synaptogenesis.	REFM 1 Bellen, Taylor, 2001: 210		
ID|FBrf0144528
TP|abstract
|Drosophila meeting abstract
MABST|A third chromosome EMS screen has identified an extensive collection of
| genes required for synaptogenesis and/ or synaptic function at the
| glutamatergic neuromuscular junction (NMJ). All mutants are embryonic/ L1
| lethal with grossly normal anatomy but abnormal movement/ paralysis and
| severely defective neurotransmission. Here, we focus on a novel locus
| called mind the gap (mtg). These mutants have normal innervation,
| musculature and NMJ synaptic architecture. Severe paralysis is due to the
| dramatically impaired neurotransmission (> 98% reduced) exhibited at the
| embryonic NMJ. Patch-clamp configuration recordings reveal parallel loss of
| evoked junctional current and miniature junctional current amplitudes.
| Direct ionotrophic application of saturating glutamate (1 mM) at the
| embryonic NMJ revealed a striking decrease in the number of functional
| glutamate receptors in the postsynaptic membrane. Immunocytochemical
| studies revealed a decrease in receptor abundance as well as an abnormal
| localization/ conformation of glutamate receptors. Over-expression the
| endogenous GluRIIA receptors using a transgenic construct (DiAntonio et
| al., J Neurosci, 1999) does not rescue the defect in glutamate receptor
| function or localization, suggesting a constitutive defect in the ability
| to produce a functional glutamatergic receptor field. Molecular analysis of
| a P-element induced mutation revealed the gene sequence of a
| prolyl-4-hydoxylase alpha subunit. This class of hydroxylases is involved
| in the stabilization of ECM proteins (i. e. collagen) and direct
| ligand-gated receptor modification, assembly and localization. Thus, the
| receptor field defect may putatively derive from either direct regulation
| of the receptors or indirect maintenance of the receptors via an
| ECM-dependent process in development. Ultrastructural analyses have
| revealed the loss of the highly structured ECM in the synaptic cleft of
| mutant NMJs; hence the name mind the gap, reflecting the specific
| perturbation of the "gap" (i. e. synaptic cleft) between mind and body. We
| are currently characterizing an allelic series of EMS, P-element, and
| P-element induced deficiencies in this region to conclusively establish the
| role of this protein in synaptogenesis. We are testing the hypothesis that
| mtg may be required for maintenance of components of the synaptic cleft
| and/ or direct glutamate receptor processing and function. Molecular
| studies are underway to confirm the involvement of the hydroxylase and its
| predicted location in the endoplasmic reticulum. These analyses will be
| presented at the meeting. This work supported by NIH GM54544 and MDA grants
| to K. S. Broadie.
AU|Fergestad
|T.
AU|Rushton
|E.
AU|Broadie
|K.
YR|2001
TI|mind the gap (MTG) encodes a prolyl-4-hydroxylase a-like enzyme required for glutamate receptor field synaptogenesis.
JR|Bellen, Taylor, 2001
PG|210
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144529	AU 1 Fernandez-Funez et al.	YR 1 2001	TP 1 Abstract	TI 1 Identification of genetic modifiers in a Drosophila model of Huntington's Disease.	REFM 1 Bellen, Taylor, 2001: 167		
ID|FBrf0144529
TP|abstract
|Drosophila meeting abstract
MABST|Huntington's disease (HD) is an autosomal dominant neurodegenerative
| disorder characterized by late-onset involuntary movements and cognitive
| impairment. HD is caused by a expansion of CAG triplets in the huntingtin
| gene, encoding a polyglutamine tract. This produces a gain-of-function of
| the Huntingtin protein that translocates to the nucleus, where it
| aggregates. To gain insight on the molecular mechanisms leading to HD
| pathology we created a fly model of the disease. We generated transgenic
| flies containing the exon 1 of the human huntingtin gene under the control
| of the UAS promoter and containing normal (16), borderline (45) and
| pathogenic (128) number of CAG repeats. We found that only flies expressing
| the expanded pathogenic repeats (encoding for 128Q) result in late-onset
| degenerative phenotypes in eye and CNS. CNS degeneration is detected in
| viability and in climbing assays, where the mobility of flies is tested.
| Taking advantage of both eye and CNS phenotypes we tested a series of
| genetic modifiers previously isolated in the lab as modifiers SCA1 -induced
| phenotypes. SCA1 is another member of the family of polyglutamine diseases
| whose common features (CAG expansion, nuclear aggregates of the proteins)
| suggest that they might share pathogenic mechanisms. We tested the SCA1
| modifiers in HD flies, and the results suggest that some of the genetic
| pathways involved in pathogenesis in both diseases are common whereas
| others are disease-specific. We are currently doing additional screens
| searching for modifiers in the HD flies. We expect that these new screens
| should identify Huntingtin-specific modifiers.
AU|Fernandez-Funez
|P.
AU|Rincon-Limas
|D.E.
AU|Fernandez-Barroso
|M.
AU|Botas
|J.
YR|2001
TI|Identification of genetic modifiers in a Drosophila model of Huntington's Disease.
JR|Bellen, Taylor, 2001
PG|167
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144530	AU 1 Fiala et al.	YR 1 2001	TP 1 Abstract	TI 1 Towards a neuronal calcium imaging in the Drosophila nervous system.	REFM 1 Bellen, Taylor, 2001: 27		
ID|FBrf0144530
TP|abstract
|Drosophila meeting abstract
MABST|We are interested in the detection of neuronal activity in the Drosophila
| nervous system. Functional optical imaging might provide a method to
| overcome the electrophysiological limitations of the fruit fly. Moreover,
| genetically encodable probes for the detection of calcium signals as a
| function of neuronal activity have been described (1), (2) and can be
| expressed in a cell-type specific manner. We are using the sensor molecules
| cameleon (1), flash-pericam, and ratiometric-pericam (2) under UAS control.
| To detect neuronal activity, we are currently establishing preparations at
| various levels of complexity. First, a neuronal cell culture is being used
| to investigate the properties of optical calcium sensor probes, allowing
| easy pharmacological access and the arrangement of cells in a single focal
| plane. Second, cameleon expression can be visualized in olfactory neurons
| of the antenna through the cuticle. We are trying to record calcium signals
| in somata within the third antennal segment under stimulation with
| different odors. Third, a window in the head capsule of the otherwise
| intact animal allows the visualization of calcium sensor probe expression
| in the brain at various levels within the olfactory system, namely
| olfactory receptor cells, projection neurons from the antennal lobe to the
| mushroom body, and Kenyon cells. Several detection systems, such as
| photomultipliers, CCD cameras, and confocal laser scanning microscopy, are
| being tested to determine under which experimental conditions calcium
| signals might be detected. First results will be presented. This work was
| supported by the Deutsche Forschungsgemeinschaft (SFB 554, BU 566/ 11 and
| FI 1/ 1) and a visiting professorship from the Tata Institute to E. B. DNA
| probes for the calcium sensors were kindly provided by Dr. R. Tsien and Dr.
| A. Miyawaki. Flies expressing cameleon 2.0 under UAS control were kindly
| provided by Dr. D. Reiff and Dr. C. Schuster. (1) Miyawaki, A., Llopis J.,
| Heim R., McCaffery J. M., Adams J. A., Ikura M., Tsien R. Y. (1997). Nature
| 388: 834-835. (2) Nagai T., Sawano A., Park E. S., Miyawaki A. (2001). Proc
| Natl Acad Sci U S A 98: 3197-3202.
AU|Fiala
|A.
AU|Diegelmann
|S.
AU|Spall
|T.
AU|Rodrigues
|V.
AU|Buchner
|E.
YR|2001
TI|Towards a neuronal calcium imaging in the Drosophila nervous system.
JR|Bellen, Taylor, 2001
PG|27
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144531	AU 1 Freeman et al.	YR 1 2001	TP 1 Abstract	TI 1 The genomics of Gcm-dependent glial cell development: Identification of Gcm target genes by computational and DNA microarray approaches.	REFM 1 Bellen, Taylor, 2001: 84		
ID|FBrf0144531
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila, the glial cells missing (gcm) gene encodes a transcription
| factor that is necessary and sufficient to activate glial fates: gcm
| mutants lack nearly all glia, and misexpression of gcm throughout the CNS
| transforms most neurons into glia. To date few transcriptional targets of
| Gcm have been identified, though many interesting glial developmental genes
| are likely to fall into this class. We have written a novel computer
| algorithm designed to search Drosophila genomic sequences for clusters of
| Gcm binding sites, and identify the flanking genes. This algorithm has
| identified nearly all known Gcm target genes (e. g. repo, loco, and pnt),
| and 375 new potential targets. A subset of these novel predicted target
| genes are (1) expressed in CNS glia; (2) potently upregulated by
| misexpression of gcm; and (3) are not expressed in the CNS in gcm mutants.
| gcm is also expressed in at least two other embryonic tissues:
| hematopoietic lineages and muscle cell attachment sites. Interestingly, we
| find subsets of our predicted target genes specifically expressed in these
| tissues, suggesting that our algorithm has also identified bona fide
| targets of gcm outside glial lineages. We will present a summary of the
| glial genes identified by this computational-expression screen, and compare
| this approach to whole embryo microarray analysis for identifying gcm
| targets. We have undertaken a detailed analysis of one of the gcm targets,
| which we are tentatively calling draper. The draper gene is expressed in
| all Repo+ CNS glia; it encodes a single-pass transmembrane domain protein
| with multiple extracellular EGF repeats and a novel intracellular domain.
| Draper protein is expressed beginning very early in glial development and
| decorates glial membranes throughout the CNS. We have recently obtained a P
| element insertion in draper and have generated protein null alleles. The
| phenotypic effects of draper mutations on embryonic glial cell development
| will be presented.
AU|Freeman
|M.R.
AU|Kim
|J.
AU|Doe
|C.Q.
YR|2001
TI|The genomics of Gcm-dependent glial cell development: Identification of Gcm target genes by computational and DNA microarray approaches.
JR|Bellen, Taylor, 2001
PG|84
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144532	AU 1 Fritz and VanBerkum	YR 1 2001	TP 1 Abstract	TI 1 Rho family GTPases regulate axon guidance at the midline of the Drosophila CNS.	REFM 1 Bellen, Taylor, 2001: 211		
ID|FBrf0144532
TP|abstract
|Drosophila meeting abstract
MABST|Forward movement of a growth cone requires coordination of actin
| polymerization, adhesion to the substrate, and myosin force generation.
| During axon pathway formation, these processes are regulated by
| intracellular signaling pathways originating from attractive and repulsive
| cues to determine the direction of growth cone movement. Attractive and
| repulsive cues may regulate growth cone motility by activating signaling
| pathways involving the Rho family of monomeric GTPases (e. g. Rho, Rac, and
| Cdc42). Rho GTPases have been implicated in axon outgrowth, filopodia and
| lamellapodia formation, and growth cone collapse. Recent studies have also
| linked these GTPases to axon guidance downstream of attractive and
| repulsive guidance receptors. Some Rho GTPases are activated by
| Son-of-Sevenless (Sos), a guanine nucleotide exchange factor recruited to
| receptor phosphotyrosines which is involved in transducing repulsive
| signals at the midline of the Drosophila CNS. To further examine the role
| of Rho GTPases in axon guidance, we tested the effects of dominant negative
| (dn) and constitutively active (ct) forms of Drosophila Rho, Rac, and Cdc42
| (expressed using the UAS-Gal4 system) on formation of the CNS, specifically
| the pCC/ MP2 pathway. As visualized at stage 16 using anti-Fasciclin II,
| axons in the pCC/ MP2 pathway do not cross the midline, so inappropriate
| midline crossing of Fasciclin II-expressing axon bundles was used as an
| assay for errors in axon guidance. When expressed alone in the pCC/ MP2
| pathway using a ftz ng -Gal4 driver, only ctRac and ctCdc42 cause defects
| in axon guidance with errors occurring in 77% and 88% of embryos,
| respectively. Mutations in molecules involved in repulsive axon guidance
| signaling were combined with GTPase expression to uncover interactions
| which might suggest how GTPases are regulated during repulsion. Disruption
| of Sos or CaM signaling has little effect on GTPase-dependent axon guidance
| defects, but heterozygous mutations in the repulsive receptor roundabout
| enhance the ctRac phenotype and cause errors in 89% of embryos expressing
| dnRho. Several GTPase expression phenotypes are modified by expression of a
| constitutively active MLCK, which increases conventional myosin activity.
| Our results suggest that the Rho family GTPases Rho, Rac and Cdc42 are
| required to modify growth cone motility in response to axon guidance cues
| during pathway formation.
AU|Fritz
|J.L.
AU|VanBerkum
|M.F.A.
YR|2001
TI|Rho family GTPases regulate axon guidance at the midline of the Drosophila CNS.
JR|Bellen, Taylor, 2001
PG|211
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144533	AU 1 Furrer and Chiba	YR 1 2001	TP 1 Abstract	TI 1 To cross or not to cross: Robo receptors in dendritic guidance at the midline.	REFM 1 Bellen, Taylor, 2001: 212		
ID|FBrf0144533
TP|abstract
|Drosophila meeting abstract
MABST|Dendrites and axon from an individual neuron exhibit different
| directionalities for their growth, and also present structural differences,
| suggesting that at least part of the mechanisms involved in their
| development could be specific to each kind of extension. When confronted
| with the same problem of crossing or not crossing the midline, wether or
| not both axon and dendrites use the same set of molecules for the
| repulsion/ attraction signal is not well known. Using single cell dye
| labeling, genetic knockout, and cell specific genetic rescue, we are
| investigating a possible role for Robo, Robo2 and Robo3, receptors for the
| signaling protein Slit secreted by the midline glia cells, in the dendritic
| guidance at the midline. Our results show that the dendritic growth in
| specific neurons is altered in these mutants. Furthermore, they suggest
| that the three different slit receptors cell-autonomously but
| differentially regulate dendritic guidance.
AU|Furrer
|M.P.
AU|Chiba
|A.
YR|2001
TI|To cross or not to cross: Robo receptors in dendritic guidance at the midline.
JR|Bellen, Taylor, 2001
PG|212
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144534	AU 1 Gafford et al.	YR 1 2001	TP 1 Abstract	TI 1 A molecular screen identifies fasciclin II as a transcriptional target of eyeless.	REFM 1 Bellen, Taylor, 2001: 128		
ID|FBrf0144534
TP|abstract
|Drosophila meeting abstract
MABST|The increasing speed with which whole genomes are being sequenced poses
| formidable challenges towards understanding the functions of individual
| genes, and the interactions of gene products in various gene circuits. The
| development of novel strategies for discovering target genes of
| transcription factors is important for understanding the regulation of gene
| expression and signaling cascades in critical developmental pathways.
| Eyeless, a Drosophila Pax-6 homolog, is a transcription factor with a
| paired and homeodomain. In order to analyze the gene circuits controlled by
| Eyeless that are important for the development of the eye and CNS, a
| strategy was developed to discover target genes. A modified PCR-selection
| assay was used to screen the Drosophila genome for segments of DNA that are
| directly bound by the Eyeless paired domain. A number of genomic DNA
| fragments were isolated, and subsequently analyzed further in vitro (yeast
| one hybrid, EMSA and footprinting) and in vivo. One fragment that was
| isolated multiple times maps to an intron of the fasciclin II gene. In
| vitro and in vivo data demonstrating that fasciclin II is a transcriptional
| target of Eyeless will be presented.
AU|Gafford
|B.
AU|Sun
|H.
AU|Kang
|Y.Y.
AU|Callerts
|P.
YR|2001
TI|A molecular screen identifies fasciclin II as a transcriptional target of eyeless.
JR|Bellen, Taylor, 2001
PG|128
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144535	AU 1 Ganguly et al.	YR 1 2001	TP 1 Abstract	TI 1 The scribble protein is essential for olfactory avoidance behavior in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 174		
ID|FBrf0144535
TP|abstract
|Drosophila meeting abstract
MABST|We have used P[ lArB]-element insertional mutagenesis to identify genes that
| contribute to olfactory behavior in Drosophila melanogaster. Disruption of
| the scribble gene results in impaired responsiveness to benzaldehyde and
| other repellant odorants. Adult smell -impaired mutants (smi97B) show a
| sexually dimorphic phenotype with stronger smell-impairment in females than
| in males. Mutant larvae display decreased chemotactic responses to
| amylacetate and benzaldehyde. Precise excision of the P[ lArB]-element
| restores wild-type olfactory behavior. A deletion line generated by an
| imprecise excision of the P-element displays a phenotype in which females
| behave normally, but males are severely smell-impaired. In smi97B flies the
| P[ lArB]-element has inserted about 1kb upstream from the transcription
| initiation site of the scribble gene. Deficiency line Df( 3R) Tl-X (97B;
| 97D1-2) and null alleles of scribble, scrib 1 and scrib 2 fail to
| complement smi97B. However, only female-specific failure to complement is
| observed with the scribble hypomorph, scrib S042405 , while inter-allelic
| complementation is observed with the hypomorphic allele scrib (j7B3) . This
| suggests the presence of alternatively spliced variants. Northern analyses
| confirm these results and reveal sex-biased transcripts that may give rise
| to the sexually dimorphic phenotype observed behaviorally. Western blot
| analyses corroborate these sex-specific expression patterns. In situ
| hybridization and immunohistochemical localization of the Scribble protein
| reveal expression throughout the CNS with enrichment of the gene product in
| the third antennal segment, the antennal nerve, and the lateral
| protocerebrum. Scribble contains 16 leucine-rich repeats and 2-4 PDZ
| domains thought to mediate protein-protein interactions. Bilder and
| Perrimon previously localized Scribble to septate junctions in embryos,
| where it is responsible for sequestering apical polarity determinants. The
| smi97B line is the first homozygous viable mutant allele of scribble and
| provides us with both larval and adult phenotypes that can be studied.
| Based on its similarity to other synaptic proteins and its localization
| pattern, we speculate that Scribble plays a role in synaptic organization
| and is essential for relay of chemosensory information in the CNS.
AU|Ganguly
|I.
AU|Mackay
|T.F.C.
AU|Anholt
|R.R.H.
YR|2001
TI|The scribble protein is essential for olfactory avoidance behavior in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|174
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144536	AU 1 Gao et al.	YR 1 2001	TP 1 Abstract	TI 1 Genetic control of neuronal morphogenesis: Role of Flamingo.	REFM 1 Bellen, Taylor, 2001: 153		
ID|FBrf0144536
TP|abstract
|Drosophila meeting abstract
MABST|We are able to visualize stereotyped dendritic morphology and axonal growth
| of single neurons in living Drosophila larvae. Using this system, we find
| that different sensory neurons in the peripheral nervous system (PNS)
| exhibit highly diverse dendritic branching patterns in a two-dimensional
| plane. Genetic manipulation of gene activity in single neurons reveals that
| flamingo plays an essential role in neuronal morphogenesis.
AU|Gao
|F.B.
AU|Sweeney
|N.
AU|Li
|W.J.
YR|2001
TI|Genetic control of neuronal morphogenesis: Role of Flamingo.
JR|Bellen, Taylor, 2001
PG|153
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144537	AU 1 Tayler et al.	YR 1 2001	TP 1 Abstract	TI 1 A tissue-specific allele of Slit uncovers its role in visual system axon targeting.	REFM 1 Bellen, Taylor, 2001: 87		
ID|FBrf0144537
TP|abstract
|Drosophila meeting abstract
MABST|The photoreceptor neurons (R-cells) of the adult Drosophila eye form highly
| stereotyped connections with target neurons in the brain's optic lobes.
| Axons from the R1-R6 subset of photoreceptor neurons make connections in
| the lamina, the most superficial optic ganglion. Axons from R7 and R8
| project through the lamina to connect with targets in the underlying optic
| ganglion, the medulla. From a genetic screen for regulators of axon
| targeting in the visual system, we have identified a homozygous viable
| recessive mutation, disrupted innervation (dui), that strongly disrupts the
| target layer selections of R1-R6 photoreceptor axons. In dui mutant larvae,
| many of the R1-R6 axons pass through the lamina and project into the
| medulla. In dui adults, this is accompanied by a failure of the medulla to
| rotate into its proper final position. Analysis of eye and target region
| development in dui animals suggests that the mutation specifically disrupts
| axon targeting. We have found that dui is an allele of slit, a gene
| encoding an extracellular guidance cue. Molecular characterization
| indicates that the dui mutation is caused by a transposon inserted ?30kb
| upstream of the Slit transcription unit. This insertion strongly reduces
| Slit expression in the visual system, but does not affect Slit expression
| in the central brain. Complementation tests indicate that slit dui acts as
| a strong loss-of-function allele of slit in the visual system, but unlike
| other strong slit alleles slit dui does not affect axon guidance at the CNS
| midline. Using this tissue-specific allele, we have characterized the role
| of slit in the visual system. In wild type, Slit protein expression is
| detected throughout the medulla extending to just beneath the R1-R6 target
| layer in the lamina. This is consistent with the loss-of-function phenotype
| observed in slit dui where R1-R6 axons inappropriately enter the medulla.
| In addition to the photoreceptors, the projections of optic lobe neurons in
| the medulla region are also disrupted in slit dui . Interestingly, members
| of the Robo family of Slit receptors are strongly and differentially
| expressed on optic lobe fibers innervating the medulla. Our analysis
| indicates that Slit is required for the proper targeting of multiple
| populations of neurons at the medulla.
AU|Tayler
|T.
AU|Robichaux
|M.
AU|Garrity
|P.A.
YR|2001
TI|A tissue-specific allele of Slit uncovers its role in visual system axon targeting.
JR|Bellen, Taylor, 2001
PG|87
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144538	AU 1 Geng et al.	YR 1 2001	TP 1 Abstract	TI 1 Rescue of photoreceptor degeneration caused by excessive calcium influx through the TRP channel.	REFM 1 Bellen, Taylor, 2001: 28		
ID|FBrf0144538
TP|abstract
|Drosophila meeting abstract
MABST|The Drosophila trp gene encodes a subunit of the highly Ca 2+ -permeable,
| light-activated channel, TRP, in Drosophila photoreceptors. Lack of TRP
| channel activity results in a rapid decay of photoreceptor potential during
| illumination, therefore the name transient receptor potential, trp.
| Recently, a semi-dominant mutation in the trp gene, Trp P365 , was
| identified and has been shown to cause the TRP Ca 2+ channels to be
| constitutively active, resulting in rapid and massive degeneration of the
| photoreceptor cells. The time course of degeneration is very rapid in Trp
| P365 homozygotes, and severe degeneration of photoreceptors is already
| present at eclosion. The time course of degeneration is slower in Trp P365
| heterozygotes, and hence , the degeneration process can be more
| conveniently monitored in heterozygotes than in homozygotes. Recently, we
| isolated a mutation inaF by P element insertional mutagenesis and showed
| that inaF gene encodes a novel protein that probably regulates the TRP
| channel activities, A partial loss of function allele, inaF P109x ,
| generated by imprecise excision of the P element, causes the TRP channel to
| nearly shut down, as in near-null trp mutants. Western analyses revealed
| that the quantity of the TRP protein in inaF P109x is reduced to
| approximately 10% that of the wild type. To see what effect inaF P109x has
| on the phenotype of Trp P365 heterozygotes, we generated inaF P109x ;; Trp
| P365 /+ double mutants and analyzed them by confocal microscopy,
| electrophysiology, and deep psudopupil analyses. Our results indicate that
| inaF P109x almost completely rescues the mutant phenotype of Trp P365
| heterozygotes. That is, inaF P109x ;; Trp P365 /+ is nearly wild type in
| all properties analyzed.
AU|Geng
|C.
AU|Pellegrino
|A.
AU|Bowman
|J.
AU|Leung
|H.T.
AU|Yin
|Z.
AU|Pak
|W.L.
YR|2001
TI|Rescue of photoreceptor degeneration caused by excessive calcium influx through the TRP channel.
JR|Bellen, Taylor, 2001
PG|28
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144539	AU 1 Ragone et al.	YR 1 2001	TP 1 Abstract	TI 1 Asymmetric divisions triggering the choice between neuronal and glial fates.	REFM 1 Bellen, Taylor, 2001: 17		
ID|FBrf0144539
TP|abstract
|Drosophila meeting abstract
MABST|The central and the peripheral nervous systems include two major cell types,
| neurons and glial cells, which differentiate from pure or mixed precursors.
| We have used the glide/ gcm gene to analyze the mixed lineages and to
| understand the molecular mechanisms leading to the fate choice between
| neurons and glia. glide/ gcm codes for a novel type of transcription factor
| and is located close to a related gene called glide2. Strikingly, the
| expression of both genes is necessary and sufficient to promote the glial
| fate in vivo, indicating a key role of these factors in glial
| differentiation. The mechanism by which the fate choice is induced is
| asymmetric distribution and inheritance of glide/ gcm RNA. By looking at a
| specific lineage, we have shown that two steps are required, asymmetric
| distribution of glide/ gcm RNA in the neuroglioblast (NGB) and maintenance
| of glide/ gcm expression in the cell that inherits most transcripts, the
| glioblast. The latter step requires the Prospero transcription factor. We
| have also found that RNA asymmetry is established progressively and that it
| only becomes apparent at NGB metaphase. In addition, we have found that
| glide/ gcm RNA displays a different subcellular localization compared to
| that of other fate determinants of the nervous system. Finally, the overall
| mode of division of the NGB is different from other asymmetric divisions
| with respect to mitotic apparatus and orientation of division. In order to
| determine the molecular and cellular bases of the fate choice between
| neurons and glia, we are now using in vivo and in vitro approaches to
| understand how glide/ gcm expression and RNA asymmetry are regulated. We
| are also analyzing the differentiation of peripheral glial cells, which
| display features similar to those of oligodendrocytes. These cells
| originate from sensory organ lineages that express glide/ gcm. glide/ gcm
| is not required in the asymmetric division that generates the glial
| precursor (GP), but is necessary in the GP to activate the glial program.
| The differentiation of peripheral glial cel ls depends on fixed cues and on
| cell-cell interactions: Notch represses glide/ gcm and thereby gliogenesis.
| Once the GP has differentiated, it stops expressing glide/ gcm and starts
| moving and proliferating. The profiles of migration and division are very
| variable, suggesting that the late steps of gliogenesis do not depend on
| lineage decisions. We are now using several approaches to determine the
| cues underlying these processes.
AU|Ragone
|G.
AU|Kammerer
|M.
AU|Van De Bor
|V.
AU|Roy
|N.
AU|Sorrentino
|S.
AU|Galy
|A.
AU|Schenck
|A.
AU|Walther
|R.
AU|Giangrande
|A.
YR|2001
TI|Asymmetric divisions triggering the choice between neuronal and glial fates.
JR|Bellen, Taylor, 2001
PG|17
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144540	AU 1 Crowner et al.	YR 1 2001	TP 1 Abstract	TI 1 How Notch steers a growth cone.	REFM 1 Bellen, Taylor, 2001: 213		
ID|FBrf0144540
TP|abstract
|Drosophila meeting abstract
MABST|With the isolation of many axon guidance molecules over the past several
| years, the central problem in axon patterning has moved on to the question
| of how these molecules collaborate to execute specific guidance decisions
| in vivo. The nine axons of the ISNb motor nerve of Drosophila separate from
| the main trunk of the intersegmental nerve (ISN) at a precise point in
| their trajectory to innervate seven body wall muscles. Although extensive
| analysis has identified many proteins which contribute to this guidance
| decision, the instructive molecules that directly induce defasciculation of
| ISNb from the ISN, and the mechanism by which they do so, have remained
| elusive. Our data demonstrate that the growth cone receptor, Notch, is the
| trigger for defasciculation of ISNb. Notch signaling in the ISNb growth
| cones is induced by contact with Notch ligand, Delta, presented on the
| adjacent cells of the ganglionic tracheal branch. Thus, the growing ISNb
| axons branch off of the ISN at precisely the point in their trajectory
| where they first encounter tracheal cells. In the absence of either Delta
| or Notch, ISNb axons never defasciculate but rather continue to track along
| the main ISN, and ISNb trajectory can be rescued by restoring Delta to the
| trachea, or Notch to the neurons, respectively. Our data further suggest
| that Notch triggers turning of ISNb axons by titrating the Abl tyrosine
| kinase and its associated adaptor protein, Disabled. Abl and Disabled
| initially promote association of ISNb axons with the ISN, but by titrating
| these proteins Notch weakens the association of ISNb growth cones with the
| ISN, permitting these axons to respond to attractive signals from target
| muscles. Consistent with this idea, Notch binds directly to Disabled
| protein, and reducing the level of Abl or Disabled suppresses the Notch
| mutant phenotype, while increasing Abl activity mimics the Notch phenotype.
| Our data suggest a new and unexpected mechanism for a growth cone guidance
| event: in this context Notch evidently determines the direction of axon
| growth by subtly tipping the balance among a variety of pre-existing
| guidance forces, and not by itself nucleating the machinery of cytoskeletal
| rearrangement. Further experiments implicate the Rac GTPase as the key
| effector of Abl/ Disabled activity in our system, and therefore as the key
| downstream target of Notch activity.
AU|Crowner
|D.
AU|Gates
|M.
AU|Giniger
|E.
YR|2001
TI|How Notch steers a growth cone.
JR|Bellen, Taylor, 2001
PG|213
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144541	AU 1 Godenschwege et al.	YR 1 2001	TP 1 Abstract	TI 1 Semaphorin 1A functions as a receptor in guiding the giant fiber of Drosophila.	REFM 1 Bellen, Taylor, 2001: 185		
ID|FBrf0144541
TP|abstract
|Drosophila meeting abstract
MABST|We investigated the role of semaphorin1a in the development of the giant
| fibers (GF) of Drosophila melanogaster. Each giant interneuron sends a
| single axon from the brain to the second thoracic segment where it
| monosynaptically contacts a motor neuron (TTMn) innervating the
| tergotrochanteral muscle. To assess the role of semaphorin1a we have used
| both gain of function and loss of function experiments and examined the
| structure and function of the GF. Gain of function experiments demonstrated
| that sema1a functions cell-autonomously in the GF. We expressed various
| wildtype and mutated sema1a constructs in the GF and examined the anatomy
| of the GF as well as the nature of the GF-TTMn synapse
| electrophysiologically. Over expression of full-length sema1a in the GF
| resulted in two major phenotypes. With low penetrance the GF stalled in the
| brain before entering the connective and did not ma ke synaptic connections
| with the TTMn. With high penetrance, the GF reached the target area but
| terminated incorrectly forming a much weaker than normal synaptic
| connection. Expression of a truncated sema1a construct, lacking the
| intracellular domain, had no effect on anatomy or physiology of the GF
| suggesting that the intracellular domain is necessary for the induction of
| the mutant phenotypes. We used loss of function experiments to demonstrate
| that the GF depends on sema1a for normal development. The GF in sema1a null
| mutants exhibited two different anatomical and physiological phenotypes.
| With high penetrance the GF was misguided towards the retina and did not
| leave the brain, which correlated with a physiological disconnection
| phenotype. With low penetrance the GF grew out of the brain and reached the
| target area where it exhibited a defective anatomical phenotype, which was
| associated with a weakened GF-TTM synapse. Preliminary electrophysiological
| results provide evidence that the synaptic defect of sema1a null mutants in
| the target area can be rescued by expression of full-length sema1a in the GF.
AU|Godenschwege
|T.A.
AU|Hu
|H.
AU|Shan
|X.
AU|Goodman
|C.S.
AU|Murphey
|R.K.
YR|2001
TI|Semaphorin 1A functions as a receptor in guiding the giant fiber of Drosophila.
JR|Bellen, Taylor, 2001
PG|185
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144542	AU 1 Goldman et al.	YR 1 2001	TP 1 Abstract	TI 1 Odorant receptor gene choice: The role of the POU domain transcription factor ACJ6.	REFM 1 Bellen, Taylor, 2001: 129		
ID|FBrf0144542
TP|abstract
|Drosophila meeting abstract
MABST|The odorant receptors (ORs) expressed by individual olfactory sensory
| neurons (OSNs) determine which odors particular cells will respond to. How
| does each individual OSN choose which odorant receptor gene( s) to express?
| The POU-domain transcription factor ACJ6 plays a key role in this process.
| Mutations in acj6 (abnormal chemosensory jump 6) cause striking olfactory
| defects. For example, single-unit recordings of individual neurons in acj6
| flies have shown that while some OSNs are unaffected by the mutation, other
| OSNs lose their response to all odors, and most interestingly, some OSNs
| acquire a novel odor-specificity. Moreover, we have found evidence that
| overexpression of ACJ6 causes an odor-specific olfactory phenotype.
| Consistent with these findings, a subset of odorant receptor genes,
| approximately 30-40% of the entire OR gene family, are not expressed in
| acj6 mutants. For example, Or33a and Or33b are normally expressed in the
| antenna, while Or33c is normally expressed in the maxillary palp. These
| three genes are arranged in a cluster that contains multiple ACJ6 consensus
| binding sites (defined for a mammalian homolog whose DNA binding domain
| shares 86% amino acid identity with that of ACJ6). All three of these genes
| fail to be expressed in acj6 mutants, as does Or85e, another gene that is
| normally expressed in the wild type maxillary palp and contains consensus
| binding sites in its promoter region. Thus, a subset of OSNs are affected
| by the acj6 mutation, and a subset of OR genes depend on ACJ6 activity for
| their expression. In an effort to determine whether ACJ6 regulates OR gene
| expression directly, we have found that ACJ6 can bind specifically to sites
| within regulatory DNA of the Or33 and Or85e genes in vitro, and we have
| established a system to study this interaction in vivo.
AU|Goldman
|A.
AU|Kreher
|S.
AU|Lessing
|D.
AU|Warr
|C.
AU|Miller
|C.
AU|Carlson
|J.
YR|2001
TI|Odorant receptor gene choice: The role of the POU domain transcription factor ACJ6.
JR|Bellen, Taylor, 2001
PG|129
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144543	AU 1 Guarnieri and Heberlein	YR 1 2001	TP 1 Abstract	TI 1 Generation and analysis of mutations that alter sensitivity to acute ethanol exposure in Drosophila.	REFM 1 Bellen, Taylor, 2001: 103		
ID|FBrf0144543
TP|abstract
|Drosophila meeting abstract
MABST|Alcohol is one of the most commonly used drugs of abuse, however the
| molecular mechanisms underlying its short term and long term effects are
| poorly understood. Human genetic analysis suggests that initial sensitivity
| to alcohol is correlated with future onset of alcoholism. Therefore, we
| expect that understanding the acute response to alcohol will allow us to
| explore questions concerning the genetic basis of alcoholism. Our lab uses
| Drosophila as a model system to study the molecular pathways underlying
| alcohol sensitivity. Upon exposure to ethanol, flies exhibit a range of
| behaviors beginning with hyperactivity, followed by loss of postural
| control and ending in complete sedation. We use a number of behavioral
| assays to quantify the behavior of flies upon acute exposure to alcohol.
| One of these assays involves the use of the inebriometer, an apparatus that
| measures the postural control of the fly. Previously our lab identified an
| allele of amnesiac as an ethanol sensitive mutant. Amnesiac is thought to
| mediate cyclic AMP production and we showed that other components of the
| cyclic AMP signaling system are required for normal ethanol sensitivity, as
| also shown in vertebrate studies. However, we suspect there are multiple
| signaling systems involved and therefore have decided to identify
| additional loci involved in mediating ethanol sensitivity. Our lab has
| generated over 1000 new homozygous viable P element insertions (P[ GAL4])
| on all three major chromosomes. We are in the process of testing these
| lines for ethanol sensitivity, as measured in the inebriometer. We have
| identified a number of lines that cause either an increase or a decrease in
| ethanol sensitivity (less than 2% of total lines screened). These mutations
| are being subjected to genetic tests to confirm that the insertion is truly
| causing the mutant phenotype and then a molecular analysis of the
| insertions will occur. Additionally these lines are being tested in a
| variety of other behavioral assays, using alcohol and other drugs of abuse.
| The results of this genetic screen will be reported.
AU|Guarnieri
|D.J.
AU|Heberlein
|U.
YR|2001
TI|Generation and analysis of mutations that alter sensitivity to acute ethanol exposure in Drosophila.
JR|Bellen, Taylor, 2001
PG|103
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144544	AU 1 Hasan et al.	YR 1 2001	TP 1 Abstract	TI 1 Inositol 1,4,5-triphosphate signaling in Drosophila.	REFM 1 Bellen, Taylor, 2001: 104		
ID|FBrf0144544
TP|abstract
|Drosophila meeting abstract
MABST|Multiple classes of stimuli including neurotransmitters, hormones, growth
| factors and sensory stimuli can lead to generation of the second messenger
| Inositol 1,4,5-trisphosphate (InsP3) within the cell. Despite its
| widespread occurrence, an understanding of the physiological significance
| of this pathway is only just beginning. A well-characterised intracellular
| target for InsP3 is the InsP3 receptor that exists as a tetrameric
| ligand-gated Ca 2+ release channel on intracellular calcium stores. In
| Drosophila a single gene, referred to as itpr, codes for the InsP3
| receptor. In order to understand the role of InsP3 signaling, in the
| context of the whole organism we have generated mutants for the itpr gene
| in Drosophila. Studies with these mutants has revealed a role for InsP3
| signaling in the regulation of larval and pupal molting, possibly through
| controlling levels of the molting hormone ecdysone (1). Our studies show
| that this control is through complex interactions with the cAMP pathway
| (2). In adult Drosophila, we find two major effects of itpr hypomorphic
| mutants, on flight and on olfactory adaptation (3). The focus of these
| defects is being analysed by expressing a cDNA for the itpr gene (4) in
| transgenic Drosophila using tissue-specific promoters. The physiological
| significance of these findings will be discussed. 1. Venkatesh, K. and
| Hasan G. (1997). Curr. Biol. 7, 500-509. 2. Venkatesh, K. et al., (2001).
| Genetics 158, 309-318 3. Deshpande et al., (2000). J. Neurobiol. 43,
| 282-288 4. Sinha, M. and Hasan, G. (1999). Gene 233, 271-276.
AU|Hasan
|G.
AU|Deshpande
|A.
AU|Joshi
|R.
YR|2001
TI|Inositol 1,4,5-triphosphate signaling in Drosophila.
JR|Bellen, Taylor, 2001
PG|104
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144545	AU 1 Hassan et al.	YR 1 2001	TP 1 Abstract	TI 1 Doing the math: Is the mouse a good model for fly development?	REFM 1 Bellen, Taylor, 2001: 130		
ID|FBrf0144545
TP|abstract
|Drosophila meeting abstract
MABST|The Drosophila proneural gene atonal (ato) is required for the development
| of chordotonal organs (CHOs), including those of the Johnston organ (JO).
| CHOs of the JO function as hearing and vertical balance receptors, similar
| to inner ear sensory organs in vertebrates. The mouse ato homologue Math1
| is required for generating all inner ear sensory hair cells. Math1 however
| does not act as a proneural gene and is not required for specification of
| precursor cells. Instead, other ato related genes, the neurogenins (ngns),
| act in precursor specification of several mammalian neuronal lineages. To
| understand the functional relationship between various ato family members,
| we performed two studies. First we asked if ato and Math1 are
| interchangeable. To this end we expressed UAS-Math1 under the control of
| ato-Gal4 and assayed the ability of Math1 to rescue the embryonic CHOs of
| ato mutants. Conversely, we knocked ato into the mouse Math1 locus and
| assayed for rescue. We find that Math1 and ato can completely replace each
| other's function in generating the appropriate cell types in mice and
| flies. The second study addressed the relationship between the proneural
| activities of ato and the ngns. Surprisingly, we find that the ngns which
| are potent neural inducers in all vertebrates, have an extremely week
| effect and rarely result in the generation of sensory organ precursors. By
| contrast, Math1, which is a very weak neural inducer in vertebrates is,
| like ato, a strong inducer of neurogenesis in the fly. Taken together,
| these data suggest that while pathways that specify cell types appear to be
| highly conserved between flies and vertebrates, pathways that direct
| competent epithelia to adopt a neural fate may not be, contrary to what
| models suggest.
AU|Hassan
|B.A.
AU|Wang
|V.Y.
AU|Zoghbi
|H.Y.
AU|Bellen
|H.J.
YR|2001
TI|Doing the math: Is the mouse a good model for fly development?
JR|Bellen, Taylor, 2001
PG|130
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144546	AU 1 Hebbar et al.	YR 1 2001	TP 1 Abstract	TI 1 Activity-dependent pruning of dorsal longitudinal flight muscle (DLM) innervation during metamorphosis.	REFM 1 Bellen, Taylor, 2001: 214		
ID|FBrf0144546
TP|abstract
|Drosophila meeting abstract
MABST|The developing adult NMJ of Drosophila has several unique features that make
| it an excellent model system to investigate mechanisms that regulate
| synaptic plasticity. Motor neurons that innervate the adult muscles are
| largely persistent larval neurons, which during metamorphosis undergo
| extensive reorganization both in the CNS as well as in the periphery. This
| remodeling is integrated with, and influenced by changes in hormonal levels
| and the developing musculature. The synaptic plasticity evident at this
| stage is more pronounced than changes that occur during larval synaptic
| growth. We are using the Dorsal Longitudinal (flight) Muscles (DLMs) as a
| model system. At the onset of metamorphosis, larval NMJs are withdrawn
| (0-12h after Puparium formation, APF) and subsequently new outgrowths are
| elaborated over the developing muscles (12-24h APF). By 24hAPF (25% of
| development), some aspects of the adult neuromuscular pattern are complete.
| These include the number of adult muscle fibers and the primary branch
| pattern. The secondary branch pattern continues to develop beyond this
| stage. Analysis of branch development during the 24-38h period has
| indicated the occurrence of pruning. Many more higher order branches are
| seen at 24h APF( 23.4� 1.2) than at 38h APF (13.0� 2.9). Using a genetic
| approach, we have investigated the role of neuronal activity on the
| formation of primary branches, the subsequent elaboration and refinement of
| higher order branches. Innervation patterns of the hyperactive mutant
| combination ether-a-go-go Shaker (eag Sh) were compared with that of wild
| type. Mutants exhibit a statistically significant increase in secondary
| branches at 24h (WT: 23.4� 1.2; eag Sh: 37 � 5.3). Interestingly, the
| mutant shows excessive pruning by 38h. (WT: 13.0� 2.9; eag Sh 8.7 � 1.6).
| Our studies indicate that neuronal activity influences arbor development
| during metamorphosis. A significant outcome of this study is the occurrence
| of pruning, which is unique to the pupal phase, and does not occur in the
| embryo/ larva. It is strikingly similar to activity dependent refinement of
| synaptic connections in vertebrates. We have initiated electrophysiological
| studies to confirm our observations. We are also investigating the process
| of synapse maturation in the context of pruning.
AU|Hebbar
|S.
AU|Killian
|K.
AU|Fernandes
|J.
YR|2001
TI|Activity-dependent pruning of dorsal longitudinal flight muscle (DLM) innervation during metamorphosis.
JR|Bellen, Taylor, 2001
PG|214
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144547	AU 1 Heidary and Fortini	YR 1 2001	TP 1 Abstract	TI 1 Identification and characterization of the Drosophila tau homolog.	REFM 1 Bellen, Taylor, 2001: 186		
ID|FBrf0144547
TP|abstract
|Drosophila meeting abstract
MABST|Neurodegenerative tauopathies, which include Alzheimer's disease and
| frontotemporal dementia and Parkinsonism linked to chromosome 17, are
| pathologically characterized by the cytoplasmic accumulation of the tau
| protein in neuronal and, in some instances, glial cells. Normally, tau is a
| highly soluble protein enriched in axons; in tau aggregates, the protein is
| abnormally phosphorylated, insoluble, and redistributed to the
| somatodendritic compartments of neurons. The tau protein is thought to
| promote axonal outgrowth and stability through its binding of microtubules.
| Whether tau aggregates contribute to neuronal loss through a direct effect
| on cellular functions such as organelle transport or an indirect effect on
| microtubule dynamics remains unanswered. To gain insight into the cellular
| role of tau in maintaining neuronal integrity and how disruption of that
| function in human disease results in neuronal loss, we have sought to
| characterize the tau protein in a genetically tractable organism. Here we
| will describe the isolation of a Drosophila tau cDNA, development of
| antibodies that recognize the encoded protein, and their use in
| characterizing the expression and subcellular localization of the fly tau protein.
AU|Heidary
|G.
AU|Fortini
|M.E.
YR|2001
TI|Identification and characterization of the Drosophila tau homolog.
JR|Bellen, Taylor, 2001
PG|186
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144548	AU 1 Hekmat-Scafe et al.	YR 1 2001	TP 1 Abstract	TI 1 Genome-wide analysis of the odorant-binding protein gene family in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 66		
ID|FBrf0144548
TP|abstract
|Drosophila meeting abstract
MABST|Olfaction is of considerable importance to many insects in behaviors
| critical for survival and reproduction including: location of food sources,
| selection of mates, recognition of colony con-specifics, and determination
| of oviposition sites. An ubiquitous, but poorly understood, component of
| the insect's olfactory system is the group of odorant-binding proteins
| (OBPs) that are present at high concentrations in the aqueous lymph
| surrounding the dendrites of olfactory receptor neurons. OBPs are believed
| to shuttle odorants from the environment to the underlying odorant
| receptors, for which they could potentially serve as odorant-presenters. We
| have show that the Drosophila genome carries 50 potential OBP genes, a
| number comparable to that of its odorant receptor genes. In contrast to
| what has been observed for the Drosophila odorant receptor genes, we found
| that the majority (75%) of potential OBP genes occur in clusters of as many
| as 9 genes. In two cases, an odorant receptor gene is located within the
| OBP gene cluster. We report an intriguing subfamily of eleven OBPs that
| share a unique C-terminal structure with three conserved cysteines and a
| conserved proline. Members of this subfamily have not previously been
| described in Drosophila or any other insect. We have performed phylogenetic
| analysis on both the Drosophila OBP gene family and the larger family of
| insect OBPs and related proteins and will present a model for the
| duplication and divergence of this large multigene family.
AU|Hekmat-Scafe
|D.S.
AU|Scafe
|C.R.
AU|McKinney
|A.J.
AU|Tanouye
|M.A.
YR|2001
TI|Genome-wide analysis of the odorant-binding protein gene family in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|66
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144549	AU 1 Hendricks et al.	YR 1 2001	TP 1 Abstract	TI 1 Clock genes have different roles in non-circadian regulation of rest and activity.	REFM 1 Bellen, Taylor, 2001: 179		
ID|FBrf0144549
TP|abstract
|Drosophila meeting abstract
MABST|We hypothesized that the Drosophila clock molecules might regulate
| non-circadian aspects of rest and/ or activity states. If so, mutations of
| clock genes would alter measures of rest/ activity duration and intensity
| in addition to circadian timing. We used the standard locomotor assay to
| study daily rest duration, activity (total daily activity, peak activity,
| and "waking" activity) both in the usual 30-min data collection bins and
| 5-min bins that allowed fine temporal analysis of rest and activity bouts.
| We compared these rest-activity measures in the 4 fully viable arrhythmic
| clock mutants (tim0, per0, cyc0 and clkjrk) and in mutants lacking the
| output neuropeptide pigment dispersing factor (pdf01). At least 25 animals
| of each mutant and background genotype were studied in constant (DD) and
| 12: 12 light-dark (LD) conditions. We found that cyc0 and to a lesser
| extent, clkjrk, mutants had greatly decreased rest (to 30% of wt in cyc0
| flies) but normal or slightly increased daily activity measures. Per0 flies
| had normal rest but decreased daily activity measures (total daily activity
| 40% of wt). Studies of heterozygotes, rescue lines, and overexpression
| transgenics verified that these abnormalities were related to mutations of
| the clock genes and not to background or non-specific effects. Clkjrk and
| cyc0 flies had longer activity bouts at the expense of rest, while per0
| flies had shorter activity bouts, lower activity rates, and more frequent
| rest-activity cycles. No consistent substantial changes in daily rest or
| activity measures could be assigned to the pdf01 or tim0 mutations. Many
| changes were apparent in activity patterns in LD compared to DD. In
| addition to some mutant-specific changes in activity response and
| anticipation of LD transitions, the mutant and background genotypes
| regardless of eye color showed a mean increase of 197% in rest, but no
| change in peak activity in LD compared to DD conditions. By studying
| animals in LD as well as DD, we found at least some degree of rest rebound
| in all clock mutants if they were deprived of >1.5 hours of consolidated
| rest. The striking exception was cyc0 flies, which could not be induced to
| exhibit >1.5H rest even in LD, and showed a further decrease in rest
| rather than the normal increase after 6H of rest-depriving stimulation. We
| conclude that clock genes have non-circadian effects on states of arousal
| in Drosophila. Because these effects differ in different mutants, they must
| be mediated through interaction with non-clock protein partners and/ or
| binding to non-clock genes, most likely in cells beyond the vLN's.
| Supported in part by HHMI (AS, ZY), NIH (AS, JCH, SL)
AU|Hendricks
|J.C.
AU|Lu
|S.
AU|Kume
|K.
AU|Yang
|Z.
AU|Sehgal
|A.
YR|2001
TI|Clock genes have different roles in non-circadian regulation of rest and activity.
JR|Bellen, Taylor, 2001
PG|179
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144550	AU 1 Hidalgo et al.	YR 1 2001	TP 1 Abstract	TI 1 Neuregulin function of Vein maintains glial survival during axon guidance in the Drosophila CNS.	REFM 1 Bellen, Taylor, 2001: 187		
ID|FBrf0144550
TP|abstract
|Drosophila meeting abstract
MABST|BLAST searches have failed to identify Drosophila Neuregulin homologues.
| Neuregulin is a neuronal molecule that controls glial survival in the
| vertebrate nervous system. Lack of trophic factors in insects could reflect
| lack of developmental plasticity in simple nervous systems and it could
| imply that insect and vertebrate nervous systems are made on different
| principles. The Drosophila protein Vein has structural similarities with
| Neuregulin. We show here that Vein functions like Neuregulin to maintain
| glial survival during Drosophila central nervous system development. We
| show that this is necessary for correct axon guidance. Functional
| conservation between Vein and Neuregulin means that insect nervous system
| development is plastic, and remarkably similar to that of vertebrates.
AU|Hidalgo
|A.
AU|Kinrade
|E.F.V.
AU|Georgiou
|M.
YR|2001
TI|Neuregulin function of Vein maintains glial survival during axon guidance in the Drosophila CNS.
JR|Bellen, Taylor, 2001
PG|187
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144551	AU 1 Hiesinger et al.	YR 1 2001	TP 1 Abstract	TI 1 An EY-FLP screen for presynaptic defects: Isolation of mutants affecting neuronal wiring and synpatogenesis.	REFM 1 Bellen, Taylor, 2001: 67		
ID|FBrf0144551
TP|abstract
|Drosophila meeting abstract
MABST|To isolate mutants that affect neuronal connectivity an eyeless-FLP screen
| was carried out (see accompanying abstract by Verstreken et al.). Mutants
| that are blind and display defects in their electroretinogram (ERG)
| recordings were selected. The ERG distinguishes mutations affecting the
| generation of electrical potentials (altered depolarization) from those
| that only fail to induce a postsynaptic response (lack of the so-called
| 'on' and 'off' transients). A signaling failure between pre-and
| postsynaptic cells has two possible causes: defects in neurotransmission or
| neuronal connectivity. To identify genes necessary for neuronal wiring and
| synaptogenesis we have established a secondary screen for mutants with
| abnormal ERGs. Adult brains were stained with Mab 24B10 allowing detection
| of fine-structural alteration of photoreceptor terminals using
| semi-automatic acquisition of 3D datasets with confocal microscopy, and
| real-time volume visualization of R7 and R8 terminal fields. About 165,000
| randomly mutagenized flies on 2L and 3R were tested in phototaxis assays,
| and 240 strains that exhibit ERG defects were established. Approximately
| one third exhibit morphological disruptions of the R7 and R8 terminals. We
| have classified these morphological mutants into the following classes: A.
| Overlapping / enlarged terminals (65%) B. Targeting errors of R7/ R8
| terminal layers (20%) C. Severe morphological disruptions, including
| pathfinding defects (10%) D. Abnormal expression levels of chaoptin (Mab
| 24B10) (5%). 80% of class A and B mutants have a small 'on' or 'off'
| response; and more than 50% exhibit abnormally small depolarizations. All
| class D mutants have no 'on' and 'off' and normal depolarizations. These
| results indicate that this screen enriches for distinct classes of subtle
| structural alterations of terminal endings where synaptic contacts are
| established. By extending this screen to the whole genome, we hope to
| uncover and characterize the pathways underlying these late developmental processes.
AU|Hiesinger
|P.R.
AU|Verstreken
|P.
AU|Schulze
|K.L.
AU|Hassan
|B.A.
AU|Mahta
|S.
AU|Cao
|Y.
AU|Zhou
|Y.
AU|Bellen
|H.J.
YR|2001
TI|An EY-FLP screen for presynaptic defects: Isolation of mutants affecting neuronal wiring and synpatogenesis.
JR|Bellen, Taylor, 2001
PG|67
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144552	AU 1 Ang et al.	YR 1 2001	TP 1 Abstract	TI 1 Dock (an Sh2/Sh3 adapter) and Pak (a serine/threonine kinase) act in a signal transduction cascade to steer olfactory axons in Drosophila.	REFM 1 Bellen, Taylor, 2001: 215		
ID|FBrf0144552
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila, antennal neurons expressing one of ~60 odorant receptor (OR)
| genes project their axons with great precision to one of ~43 glomeruli in
| the antennal lobe. The precise projection of axons expressing a given OR
| gene to a specific glomerulus, while avoiding all other glomeruli, suggests
| that the olfactory axons are specifically attracted by their target
| glomeruli, and are either unattracted or repelled by nontarget glomeruli.
| This implies the existence of attractive and/ or repulsive guidance cues
| presented by cells in the developing antennal lobe. However, the nature of
| these cues and the mechanisms by which they steer antennal axons to their
| targets are completely unknown. In our previous work we showed that dock
| and Pak, function in a signal transduction pathway to guide precise
| navigation of retinal growth cones. We now discovered that both dock and
| Pak are required for precise wiring of the fly olfactory map.
| Loss-of-function dock and Pak mutants show severe disruptions of antennal
| axon projections. Instead of converging upon specific glomeruli, axons
| expressing given OR genes terminate in multiple ectopic locations in the
| antennal lobe. Other termini transgress their boundaries to invade
| surrounding glomeruli. Mosaic analyses showed that dock and Pak genes
| function within the antennae, very likely in antennal neurons. Examination
| of cell-fate markers showed that the antennal neurons in dock and Pak
| mutants exhibit normal profiles of gene expressions. Hence, dock and Pak do
| not function in antennal neuron differentiation. We hypothesize that the
| Dock and Pak proteins act as components of a signaling cascade that steers
| olfactory axons precisely to their targets in Drosophila. To the best of
| our knowledge, Dock and Pak are the first known signaling molecules to be
| identified for olfactory axon guidance. Further analyses of this signaling
| pathway will provide insight into the molecular mechanisms of olfactory
| axon targeting and may shed light on developmental rules shared between the
| odotopic and retinotopic maps.
AU|Ang
|L.H.
AU|Stepensky
|V.
AU|Hing
|H.
YR|2001
TI|Dock (an Sh2/Sh3 adapter) and Pak (a serine/threonine kinase) act in a signal transduction cascade to steer olfactory axons in Drosophila.
JR|Bellen, Taylor, 2001
PG|215
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144553	AU 1 Hofmeyer et al.	YR 1 2001	TP 1 Abstract	TI 1 Optomotor-blind in optic lobe development.	REFM 1 Bellen, Taylor, 2001: 188		
ID|FBrf0144553
TP|abstract
|Drosophila meeting abstract
MABST|The optomotor-blind (omb) gene was first isolated in a screen for aberrant
| optomotor behavior. Subsequently it was shown that in several viable omb
| mutant alleles various aspects of optic lobe neuroanatomy are disrupted.
| Furthermore, omb plays a role in many other developmental processes
| including appendage patterning, eye development and tergit pigmentation.
| Previously, deletion mutants, whic h remove increasingly larger parts of
| the omb downstream "optic lobe regulatory region" (OLR), have been analyzed
| in detail with regard to the neuroanatomical and behavioral phenotypes.
| Deletion of the subregion OLR3, lying more than 100 kb downstream of the
| promoter, leads to the loss of a subset of the lobula plate giant neurons
| as well as to a reduction in fiber number in the anterior optic tract. On
| the behavioral level, the large field response is impaired. Deletion of
| OLR2 and 3 causes a defective inner optic chiasm (IOC) and an increase in
| severity of the behavioral phenotype. In an attempt to link these
| phenotypes to alterations of the omb expression pattern caused by deletion
| of regulatory elements, we performed a detailed analysis of omb expression
| in wildtype and mutant larval optic lobes. In OLR2 + 3 deletion mutants,
| omb expression was shown to be reduced in a subset of cells of the medulla
| cortex as well as in glial cells of the inner optic chiasm. With the aim of
| generating genetic tools for the perturbation of isolated aspects of optic
| lobe development, we dissected the entire OLR into 10 genomic fragments and
| analyzed their enhancer activity in transgenic flies. We identified an
| enhancer within OLR2 (omb-C) which is active in glial cells of the inner
| and outer optic chiasm. Deletion of a genomic region containing this
| enhancer leads to a loss of omb expression from inner optic chiasm glia and
| to a structural disruption of the adult IOC. Also, within OLR3 we
| identified an enhancer element (omb-K) which is responsive to wg signaling
| and contains a functional TCF/ LEF-1 binding site. While omb-K activity
| overlaps with both wg and omb expression in the glia proliferation centers
| (GPC) of larval optic lobes, the role of this regulatory elements remains
| unclear since its deletion does not lead to a detectable loss of omb
| expression from the GPC.
AU|Hofmeyer
|K.
AU|Lickert
|H.
AU|Pfulgfelder
|G.O.
YR|2001
TI|Optomotor-blind in optic lobe development.
JR|Bellen, Taylor, 2001
PG|188
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144554	AU 1 Hsu and Chiba	YR 1 2001	TP 1 Abstract	TI 1 Endocytosis in postsynpatic cells regulates the initiation of synpatogenesis.	REFM 1 Bellen, Taylor, 2001: 216		
ID|FBrf0144554
TP|abstract
|Drosophila meeting abstract
MABST|The mechanisms by which postsynaptic cells regulate the timing of
| synaptogenesis are not well understood. Previous studies have shown that
| endocytosis of the Commissureless protein (COMM) in postsynaptic muscle
| cells is correlated with the initiation of synaptogenesis (Wolf et al.,
| 1998). We are now testing the general model that synaptogenesis can be
| initiated by resurfacing the postsynaptic membrane through
| spatio-temporally regulated endocytosis. To control endocytosis, we
| utilized the temperature-sensitive shibire mutant gene (UAS-shi ts1 ;
| source: T. Kitamoto) which encodes for dynamin, a GTPase required for the
| fission of endocytic vesicles from the plasma membrane. The shi ts1 protein
| works in a dominant negative manner while expressed in a wild type
| background. After heat treatment, endocytic activity was partially blocked
| in wild type embryos which expressed shi ts1 . Embryos expressing the
| UAS-shi ts1 construct in muscles received a 5 hour heat treatment (30 o C)
| starting at stage 14, when motoneuron axons begin to navigate muscles, and
| continuing until late stage 16, when the axons would have normally
| initiated synaptogenesis. By partially blocking the endocytosis in
| postsynaptic muscle cells, we found that embryos which expressed the
| shibire protein in their muscles have 27% lower innervation rates at
| specific sites, such SNb and SNd when compared to controls. The results
| support the model that timely endocytosis in postsynaptic cells plays an
| important role in the initiation of synaptogenesis.
AU|Hsu
|S.
AU|Chiba
|A.
YR|2001
TI|Endocytosis in postsynpatic cells regulates the initiation of synpatogenesis.
JR|Bellen, Taylor, 2001
PG|216
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144555	AU 1 Huang et al.	YR 1 2001	TP 1 Abstract	TI 1 Rolling blackout (rbo) encodes a multipass transmembrane protein which mutates to confer temperature sensitive paralysis and blindness.	REFM 1 Bellen, Taylor, 2001: 29		
ID|FBrf0144555
TP|abstract
|Drosophila meeting abstract
MABST|P-element and EMS mutagenesis have identified a gene required for embryonic
| development and, in conditional mutants, the acute maintenance of
| coordinated mobility and phototransduction. Homozygous or heterozygous
| conditional mutant alleles display slow, temperature sensitive adult
| paralysis (38 o C degree, <4 min) and complete, reversible loss of
| phototransduction (38 o C degree, <5 min) in electroretinogram (ERG)
| records in the adult eye. These conditional phenotypes gave rise to the
| gene name of rolling blackout (rbo) reflecting the conditional loss of
| electrical function. Cellular analyses of synaptic architecture and
| function are on-going. Studies with synaptic markers (e. g. anti-CSP) have
| revealed altered synaptic morphology at the larval neuromuscular junction
| (NMJ). Mutants display inappropriate branching in synaptic arbors, and
| overgrowth to inappropriate neighboring membrane. Using positional and
| molecular mapping methods, we have identified the cytological location of
| rbo. Mutant P-element insertion alleles indicate that rbo encodes a
| conserved multipass transmembrane protein of unknown function. A genomic
| construct of this gene completely rescues the rbo phenotypes, including the
| ts paralysis and ERG loss. Current studies are focussing on identifying the
| subcellular protein location and its precise function in neuronal
| signaling. These analyses will be presented at the meeting. This work
| supported by NIH GM54544 and MDA grants to K. B.
AU|Huang
|F.D.
AU|Speese
|S.
AU|Smith
|M.
AU|Broadie
|K.
YR|2001
TI|Rolling blackout (rbo) encodes a multipass transmembrane protein which mutates to confer temperature sensitive paralysis and blindness.
JR|Bellen, Taylor, 2001
PG|29
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144556	AU 1 Iwanami and Hiromi	YR 1 2001	TP 1 Abstract	TI 1 branchless controls the outgrowth of eye disc development.	REFM 1 Bellen, Taylor, 2001: 217		
ID|FBrf0144556
TP|abstract
|Drosophila meeting abstract
MABST|Drosophila has single FGF gene, branchless (bnl), whose only known function
| is the patterning of tracheal branching and the control of tracheal cell
| migration. Expression of bnl is not restricted to the tracheal system, but
| is also found in restricted regions of imaginal discs, which are epithelial
| sheets that generate the exterior structure of the adult. Using the mosaic
| analysis method, we analyzed the function of bnl in Drosophila eye disc
| development. bnl was required for the eye imaginal disc outgrowth and the
| proper eye morphogenesis. Interestingly, bnl is also required to repress
| the wingless expression in dorsal and ventral margins behind the furrow.
| Though bnl is also expressed in the margins in ahead of the furrow, the
| requirement of bnl for the wg repression is only behind the furrow. This
| suggests another signals behind the furrow might cooperate with bnl
| signaling to repress wg expression. In vertebrates, the fibroblast growth
| factor (FGF) family consists of at least 15 structurally related
| polypeptide growth factors that play crucial roles in morphogenetic
| patterning in many aspects of development. Our data indicate that
| Drosophila eye imaginal disc development has a similarity to vertebrate
| limb bud growth through FGF function. The role of FGF signaling in eye
| development will be discussed.
AU|Iwanami
|M.
AU|Hiromi
|Y.
YR|2001
TI|branchless controls the outgrowth of eye disc development.
JR|Bellen, Taylor, 2001
PG|217
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144557	AU 1 zur Lage et al.	YR 1 2001	TP 1 Abstract	TI 1 Expected and unexpected phoenotypes of mutations in the suspected proneural gene amos.	REFM 1 Bellen, Taylor, 2001: 5		
ID|FBrf0144557
TP|abstract
|Drosophila meeting abstract
MABST|In the Drosophila PNS, bHLH-encoding proneural genes are required for the
| determination of sense organ precursors. When they are mutated, specific
| subsets of sense organ precursors fail to form. Proneural genes include
| achaete-scute and atonal. We recently isolated a further candidate
| proneural gene, called amos. Indirect evidence suggested that amos is
| required for olfactory sensilla, but there was no definitive evidence of
| this. We have now isolated amos mutations. Sequence analysis of the alleles
| suggest that they include hypomorphs and a protein null. The mutations are
| viable, but the adult flies completely lack two kinds of olfactory sensilla
| (sensilla basiconica and trichodea), demonstrating that amos is absolutely
| required for these olfactory sensilla. The mutant flies, however, also have
| unexpected features: ectopic external sense organs differentiate
| inappropriately on the antenna. This feature is not a normal characteristic
| of proneural gene mutations. We have investigated the basis of this
| phenotype and consider why it is unique to amos. To establish whether amos
| is a 'true' proneural gene, we have extensively characterised how olfactory
| sense organ precursors arise during antennal development and have related
| this to the expression and function of amos using amos antibodies, mutants
| and promoter constructs. This has identified the precursors that are amos-dependent.
AU|zur Lage
|P.
AU|Prentice
|D.R.A.
AU|Holohan
|E.
AU|Jarman
|A.P.
YR|2001
TI|Expected and unexpected phoenotypes of mutations in the suspected proneural gene amos.
JR|Bellen, Taylor, 2001
PG|5
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144558	AU 1 Jasper et al.	YR 1 2001	TP 1 Abstract	TI 1 Transcriptome analysis in Drosophila by SAGE.	REFM 1 Bellen, Taylor, 2001: 68		
ID|FBrf0144558
TP|abstract
|Drosophila meeting abstract
MABST|JNK signaling regulates morphogenetic processes like dorsal closure and
| thorax closure during Drosophila development. We identified genes
| responsive to JNK signaling in the Drosophila embryo on a genome -wide
| scale using Serial Analysis of Gene Expression (SAGE). Two main groups of
| genes were found: genes involved in the regulation of the cytoskeleton and
| genes involved in cellular stress responses. Detailed genetic and cellular
| analysis of one of the cytoskeletal regulators, chickadee, confirmed its
| function downstream of JNK signaling to mediate dorsal closure. The
| identification of stress response genes as JNK target genes suggests a
| complex biological function of JNK signaling in Drosophila as it is also
| observed in mammals. SAGE thus proved to be a valuable tool for the
| dissection of developmental pathways in Drosophila. Furthermore, since it
| does not require large amounts of mRNA, it is the method of choice for
| transcriptome analysis from purified cell populations. We used SAGE to
| analyze the transcriptional changes of cells in the Drosophila eye imaginal
| disc when undergoing proliferation arrest and initiating differentiation.
| We purified cells from eye discs expressing GFP under the control of
| GMR-Gal4 by FACS. SAGE libraries were produced from 800'000 cells each of
| the purified differentiating and the proliferating populations. A
| comparison of these two libraries identified novel genes putatively
| involved in cellular proliferation and neuronal differentiation in the
| Drosophila eye. Furthermore, comparison of these two libraries with the
| embryonic libraries produced earlier identified genes specific for cells
| determined to an "eye" fate. Preliminary functional data on some of the
| identified novel genes will be presented.
AU|Jasper
|H.
AU|Benes
|V.
AU|Schwager
|C.
AU|Sauer
|S.
AU|Ansorge
|W.
AU|Bohmann
|D.
YR|2001
TI|Transcriptome analysis in Drosophila by SAGE.
JR|Bellen, Taylor, 2001
PG|68
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144559	AU 1 Jefferis et al.	YR 1 2001	TP 1 Abstract	TI 1 Projection neuron prespecification in the olfactory map of Drosophila.	REFM 1 Bellen, Taylor, 2001: 218		
ID|FBrf0144559
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila and mice, olfactory receptor neurons (ORNs) expressing the
| same receptors have convergent axonal projections to specific glomerular
| targets in the antennal lobe/ olfactory bulb, creating an odour map in this
| first olfactory structure of the CNS. How is this odour map transferred
| further into the brain? We have used the MARCM method to perform a
| systematic clonal analysis of Drosophila antennal lobe projection neurons
| (PNs), which send dendrites into single glomeruli and axons to higher brain
| centres. We demonstrate that PNs are prespecified by lineage and birth
| order to synapse with specific incoming ORN axons and therefore to carry
| specific olfactory information. Furthermore, PNs innervating specific
| glomeruli have characteristic axonal projections in higher olfactory
| centres. Therefore, this prespecification could be the mechanism which
| couples PN dendritic and axonal projections, enabling innate recognition of
| odorants. Developmental studies lead us to hypothesise that recognition
| molecules ensure reciprocally specific connections of ORNs and PNs. These
| studies also uncover a previously unanticipated role for precise dendritic
| targeting by postsynaptic neurons in determining connection specificity.
AU|Jefferis
|G.S.X.E.
AU|Maris
|E.C.
AU|Stocker
|R.F.
AU|Luo
|L.
YR|2001
TI|Projection neuron prespecification in the olfactory map of Drosophila.
JR|Bellen, Taylor, 2001
PG|218
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144560	AU 1 Jhaveri and Rodrigues	YR 1 2001	TP 1 Abstract	TI 1 Sensory neurons of atonal lineage provide instructive cues for patterning of glomeruli in the antennal lobe of Drosophila.	REFM 1 Bellen, Taylor, 2001: 6		
ID|FBrf0144560
TP|abstract
|Drosophila meeting abstract
MABST|Sensory neurons from the antennal sense organs project to the olfactory lobe
| and terminate in distinct structures termed glomeruli. We have shown that
| while the ability to project to the lobe is an autonomous property of all
| neurons, their segregation into glomeruli is not. Sensory neurons that
| project from one of the three sensilla -those specified by the atonal
| gene-provide instructive cues for patterning the glomeruli. A complete loss
| of atonal function results in an aglomerular lobe, while some pattern is
| detectable in weak hypomorphic alleles. Further, normal glomerular patterns
| are seen in mutants of the lozenge locus in which about 60% of the sensory
| neurons fail to form. This suggests that a subset of the Atonal-dependent
| neurons are necessary and sufficient for glomerular patterning. Sense
| organs of the Atonal lineage are gliogenic and give rise to about 70% of
| the glia in the antenna. These glia are missing in mutants defective in
| atonal function; we have shown that these glia do not play a role in lobe
| patterning. Misexpression of dominant negative cdc42 (a Rho family GTPase)
| in antennal glial cells affected the fasiculation of the sensory axons,
| suggesting that the glial cells played an important role in fasciculation
| of sensory neurons in the antenna. In this case, however, analyses by
| various synaptic markers revealed that the lobe morphology was unaffected.
| The signaling mechanism between the Atonal-dependent and the rest of the
| neurons needs further investigation.
AU|Jhaveri
|D.
AU|Rodrigues
|V.
YR|2001
TI|Sensory neurons of atonal lineage provide instructive cues for patterning of glomeruli in the antennal lobe of Drosophila.
JR|Bellen, Taylor, 2001
PG|6
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144561	AU 1 Kalidas et al.	YR 1 2001	TP 1 Abstract	TI 1 Transgenic RNAi reveals a role for Gq signaling in olfaction.	REFM 1 Bellen, Taylor, 2001: 69		
ID|FBrf0144561
TP|abstract
|Drosophila meeting abstract
MABST|RNAi is a potent method to mimic loss-of-function mutations in C. elegans,
| Drosophila and most recently vertebrate tissue culture cells. Attempts to
| utilize transgenic RNAi "snapback" constructs in Drosophila to reduce
| specific gene products in specific tissues have only mimicked weak alleles.
| We have used a novel RNAi construction that utilizes genomic-cDNA fusions
| to generate snap-back RNA molecules. We have targeted mRNA encoding
| dGqa-49b in the eye to evaluate the effectiveness and cell autonomy of this
| approach, and in the olfactory neurons to evaluate the role of Gq signaling
| in olfaction. When expressed in R1-R6 photoreceptors, this RNAi construct
| dramatically reduces dGqa-1 expression, and produces a corresponding
| reduction in light sensitivity that rivals a strong genetic mutant. To
| explore the signal transduction pathways important for chemical senses in
| Drosophila, we have expressed this RNAi construct in olfactory neurons. We
| cloned the upstream regulatory sequences that drive expression of the OR83b
| receptor, a putative odorant receptor expressed specifically in all
| olfactory neurons. We used this promoter to drive expression of dGqa-49b
| RNAi using the Gal4-UAS system. Our results indicate that dGqa is an
| important mediator of a subset of olfactory responses, and that
| genomic-cDNA fusion RNAi is an effective tool to study loss of function
| phenotypes in the nervous system.
AU|Kalidas
|S.
AU|Olsen
|J.
AU|Ranganhan
|R.
AU|Smith
|D.
YR|2001
TI|Transgenic RNAi reveals a role for Gq signaling in olfaction.
JR|Bellen, Taylor, 2001
PG|69
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144562	AU 1 Kang et al.	YR 1 2001	TP 1 Abstract	TI 1 CRASH in flies: The L1 CAM homolog neuroglian is essential for mushroom body and central complex development.	REFM 1 Bellen, Taylor, 2001: 189		
ID|FBrf0144562
TP|abstract
|Drosophila meeting abstract
MABST|Cell adhesion molecules are critical for normal development and function of
| the brain, and are intrinsic parts of the mechanisms that control growth
| cone guidance and axon outgrowth and fasciculation. Cell adhesion molecules
| comprise cadherins, integrins, selectins, and members of the immunoglobulin
| superfamily. L1 CAM-related genes are members of the immunoglobulin
| superfamily important for normal brain development. In humans, mutations in
| the L1 gene cause the CRASH syndrome, with the most typical symptoms
| including Corpus callosum agenesis, Retardation, Adducted thumbs, Shuffling
| gait and Hydrocephalus. We are studying neuroglian, the Drosophila homolog
| of L1CAM, to address the mode of action of L1CAM-related genes in brain
| development and function. Analysis of the expression pattern of the
| neuronal-specific form of neuroglian in brain development, and of the
| neuroglian mutant phenotype, have revealed a distinct role for neuroglian
| in mushroom body and central complex development. We have determined that
| the molecular defect causing the temperature-sensitive allele nrg 3
| consists of two point mutations in the immunoglobulin domains of
| Neuroglian, analogous to missense mutations identified in human L1CAM. At
| the restrictive temperature, these mutations cause the retention of the
| Neuroglian protein in the endoplasmic reticulum or Golgi apparatus. The
| remarkable structural and functional similarities between vertebrate L1CAM
| and Drosophila neuroglian in the brain makes Drosophila neuroglian an
| excellent model system to study the role of L1CAM family members in brain
| development, and thus to explore the molecular mechanism of the CRASH syndrome.
AU|Kang
|Y.Y.
AU|Hiesinger
|R.
AU|Callaerts
|P.
YR|2001
TI|CRASH in flies: The L1 CAM homolog neuroglian is essential for mushroom body and central complex development.
JR|Bellen, Taylor, 2001
PG|189
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144563	AU 1 Karagiosis et al.	YR 1 2001	TP 1 Abstract	TI 1 Characterization of moesin in Drosophila retinal development: A key player in rhabdomere morphogenesis.	REFM 1 Bellen, Taylor, 2001: 131		
ID|FBrf0144563
TP|abstract
|Drosophila meeting abstract
MABST|The molecular mechanisms of morphogenesis are a central question of
| developmental cell biology; how do cells organize the complex, higher order
| protein assemblies that shape a cell to its specialized task? Morphogenesis
| of the Drosophila rhabdomere, the photosensitive membrane organelle of
| compound eye photoreceptors, offers an attractive model system for
| investigating membrane-cytoskeleton interactions in development. Drosophila
| rhabdomeres are enormously amplified apical cell surfaces folded into a
| virtually crystalline array of photosensitive microvilli. Morphogenesis of
| this "membrane crystal" is directed by the orderly assembly of the cortical
| actin cytoskeleton and its attachment to the plasma membrane. A plausible
| candidate for the critical anchorage between the rhabdomere and the actin
| cytoskeleton is Dmoesin, the Drosophila homolog of moesin. Moesin, as well
| as the other members of the ERM (erzin-radixin-moesin) family, have been
| demonstrated to function as a plasma membrane-cytoskeleton linker in a
| variety of cell types and implicated in cytoskeletal reorganization at the
| dynamic actin-plasma membrane interface. My objective is to characteri ze
| moesin's role in rhabdomere morphogenesis using a combination of cellular,
| molecular, and genetic approaches.
AU|Karagiosis
|S.A.
AU|Nikivorova
|O.
AU|Fehon
|R.
AU|Ready
|D.F.
YR|2001
TI|Characterization of moesin in Drosophila retinal development: A key player in rhabdomere morphogenesis.
JR|Bellen, Taylor, 2001
PG|131
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144564	AU 1 Karunanithi et al.	YR 1 2001	TP 1 Abstract	TI 1 Differences in quantal size between motor inputs is determined by vesicle size in normal and dlg mutants Drosophila glutametergic synapses.	REFM 1 Bellen, Taylor, 2001: 30		
ID|FBrf0144564
TP|abstract
|Drosophila meeting abstract
MABST|How ultrastructural and molecular differences amongst synapses confer
| functional diversity remains unclear. In Drosophila, we investigated
| whether ultrastructural differences between two motor inputs innervating
| the same muscle cell produce functional differences. Motor neurons RP3 and
| 6/ 7b innervating the larval ventral longitudinal muscle 6, segment 3,
| supply synaptic boutons which differ structurally; RP3's boutons (Type Ib)
| are on average larger, and possess more synapses, active zones, and
| mitochondria than boutons supplied by 6/ 7b (Type Is). In electron
| micrographs we also discovered that wild type Is boutons contained synaptic
| vesicles which are significantly larger than those in Ib boutons. Using a
| macropatch electrode to record miniature excitatory junctional currents
| (mEJCs) from individual boutons, we found that Is boutons generate
| significantly larger mean quantal sizes than Ib boutons, corresponding to
| differences in vesicle size. Mutants of the discs-large (dlg) tumor
| suppressor gene exhibit larger than normal synapse and vesicle size.
| Quantal variance at wild type and dlg synapses are large and correspond
| with variation in vesicle volume. The linear relationship between mean
| quantal size and mean vesicular volume indicates that the amount of
| released glutamate depends on vesicular volume. The timecourse of quantal
| currents corresponds with differing vesicle sizes; this can be accounted
| for by differences in the cleft glutamate concentration. Thus, differences
| in synaptic strength originate in part presynaptically through differences
| in vesicle size. Supported by grants from NSERC to HLA.
AU|Karunanithi
|S.
AU|Marin
|L.
AU|Wong
|K.
AU|Atwood
|H.L.
YR|2001
TI|Differences in quantal size between motor inputs is determined by vesicle size in normal and dlg mutants Drosophila glutametergic synapses.
JR|Bellen, Taylor, 2001
PG|30
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144565	AU 1 Kelly et al.	YR 1 2001	TP 1 Abstract	TI 1 Ca<up>2+</up>-dependent interaction between stonedB and Dap-160.	REFM 1 Bellen, Taylor, 2001: 31		
ID|FBrf0144565
TP|abstract
|Drosophila meeting abstract
MABST|Mutations at the stoned locus of Drosophila melanogaster have been shown to
| alter synaptic transmission, and it has been proposed that stoned acts in
| the synaptic vesicle recycling pathway. Cl oning of the stoned gene
| revealed that this locus produces a dicistronic transcript that is
| translated into two proteins STNA and STNB. The STNB protein (138kDa) is a
| novel protein but shows homology in a C-terminal domain to the m subunits
| of the clathrin associated protein complexes AP1 and AP2. Like m-2, STNB
| has been shown to be associated with synaptic vesicles by binding to the
| integral synaptic protein synaptotagmin. STNB also contains seven "NPF"
| sequences known to be recognised by EH-domain encoding proteins, as well as
| two proline rich domains which are possible SH3 domain binding sites.
| Viable mutations at the stoned locus show lethal interactions with
| mutations at the shibire (dynamin) locus (Petrovich et al., 1993),
| suggesting a role for stoned in vesicle recycling. The dynamin-binding
| protein Dap-160 contains both EH and SH3 -domains and therefore has the
| potential to interact with STNB. Here we describe a Ca 2+ -dependent
| interaction between Dap-160 EH domain B and the amino-terminal region of
| STNB, and speculate that STNB may be responsible for the Ca 2+ -dependent
| recruitment of dynamin, via Dap-160, to invaginating synaptic vesicles
AU|Kelly
|L.E.
AU|Roos
|J.
AU|Phillips
|M.
YR|2001
TI|Ca<up>2+</up>-dependent interaction between stonedB and Dap-160.
JR|Bellen, Taylor, 2001
PG|31
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144566	AU 1 Kibler et al.	YR 1 2001	TP 1 Abstract	TI 1 The X-chromosomal mutation mbu affects mushroom body development.	REFM 1 Bellen, Taylor, 2001: 190		
ID|FBrf0144566
TP|abstract
|Drosophila meeting abstract
MABST|mbu P1 (mushroom bodies undersized) was isolated in a histological screen
| for structural mushroom body defects as a viable X-chromosomal P-element
| insertion due to a ~50% reduction of the mushroom body calyx volume in both
| male and female flies. Plasmid rescue and jump-out experiments show that
| two P( lacW)-elements are inserted in the 5'-region of the casein kinase II
| �1 subunit gene (10E2) and cause the mushroom body phenotype. The mushroom
| body phenotype can be rescued in males both by a 6 kb genomic fragment and
| by expressing the CKIIb1-cDNA under the control of different Gal4 enhancer
| trap lines. CKIIb1 is mutable to lethality by imprecise P-element excision.
| This lethality can be rescued by the 6 kb genomic fragment. Three conserved
| regions of CKIIb1 have been in-vitro mutagenized. This include Ser-residues
| of a putative N-terminal autophosphorylation site, Cys-residues that form a
| metal binding finger and an Arg-residue which is part of a motiv that might
| be a destruction box. Expressing those cDNA's in the mbu P1 -mutant
| background might shed light on the in-vivo function of these conserved
| regions of CKIIb1 during mushroom body development. Immunohistochemical
| staining of the adult mushroom body neuropil detects all mushroom body
| lobe-systems although the total number of Kenyon cells is severly reduced.
| Wether mbu P1 affects mushroom body neuroblast determination or
| proliferation or induces apoptosis in a subset of Kenyon cells is subject
| of our present research.
AU|Kibler
|E.
AU|Melzig
|J.
AU|Heisenberg
|M.
AU|Raabe
|T.
YR|2001
TI|The X-chromosomal mutation mbu affects mushroom body development.
JR|Bellen, Taylor, 2001
PG|190
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144567	AU 1 Kidokoro and Suzuki	YR 1 2001	TP 1 Abstract	TI 1 Multiple defects in synaptic transmission in Drosophila synaptotagmin-null mutant embryos.	REFM 1 Bellen, Taylor, 2001: 32		
ID|FBrf0144567
TP|abstract
|Drosophila meeting abstract
MABST|Synaptotagmin is considered to be involved in multiple functions in synaptic
| vesicle recycling and fusion. To determine its functional roles in synaptic
| transmission we examined synaptic currents in Drosophila synaptotagmin
| (syt)-null mutant embryos at the neuromuscular junction, using the
| patch-clamp techniques. Fusion of synaptic vesicles was induced by various
| means, namely, nerve -stimulation, high K + stimulation, hypertonicity,
| cAMP and Ca 2+ -ionophore application. In the mutants nerve-stimulation did
| not evoke synch ronized synaptic currents as reported previously. In
| solutions containing 35 mM K + and 3 �M tetrodotoxin (TTX), in the mutants
| the frequency of miniature synaptic currents (mSCs) was higher than that in
| normal saline but not different than wild -type. Nor were mSC amplitudes
| different. The frequency increased with Ca 2+ concentrations in externa l
| saline similarly in the mutants and wild-type. Thus mSCs were not affected
| by the syt mutation. A hypertonic solution (420 mM sucrose was added to Ca
| 2+ -free external saline) induced robust quantal transmitter release in
| wild-type embryos, but in the mutants only a small response was observed.
| Since the hypertonicity response is probably evoked only when the partial
| SNARE complex is formed, this result suggests that formation of the complex
| or recruitment of vesicles to form the complex is impaired in the mutants.
| Forskolin, an activator of adenylyl cyclase, increased mSC frequency in the
| absence of external Ca 2+ in wild-type embryos. In contrast, virtually no
| response to forskolin was observed in the mutants. Since cAMP may be
| involved in recruitment of vesicles for release, this result suggests a
| defect in vesicle mobilization in the mutants. Ca 2+ ionophores, A23187 or
| ionomycin, increased mSC frequency in wild-type embryos by elevating Ca 2+
| concentrations in the terminal. In the mutants, however, ionophores
| increased mSC frequency to much lesser extent. Thus, although the vesicle
| fusion mechanism in the mutants responds to Ca 2+ , high frequency release
| is severely impaired. Taken together these results, it appears that
| Synaptotagmin is indispensable for nerve-evoked fast synaptic transmission
| but not required for slow spontaneous release. In addition Synaptotagmin
| appears to be involved in vesicle recruitment.
AU|Kidokoro
|Y.
AU|Suzuki
|K.
YR|2001
TI|Multiple defects in synaptic transmission in Drosophila synaptotagmin-null mutant embryos.
JR|Bellen, Taylor, 2001
PG|32
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144568	AU 1 Kim and Chiba	YR 1 2001	TP 1 Abstract	TI 1 Growth cone pathfinding and filopodial dynamics are mediated separately by Cdc42 activation.	REFM 1 Bellen, Taylor, 2001: 219		
ID|FBrf0144568
TP|abstract
|Drosophila meeting abstract
MABST|While evidence exists that activation of the small GTPase Cdc42 affects
| axonal development, its specific roles within a growth cone, regulating
| filopodial dynamics and pathfinding, are not well delineated. To evaluate
| the general model that Cdc42 activation regulates growth cone navigation by
| promoting filopodial activity, we adopted a live analysis strategy that
| uses transgenic Drosophila lines in which neurons co-expressed
| constitutively active Cdc42 (Cdc42 V12 ) and membrane-targeted GFP. We
| found that growth cones that displayed pathfinding defects exhibited little
| change in their filopodial activity, while others without pathfinding
| defects exhibited an approximately 50% increase in their filopodial
| activity. Moreover, effector mutations that were added to the
| constitutively active Cdc42 (Cdc42 V12C40 and Cdc42 V12A37 ) exerted little
| influence over filopodial activity but nullified the pathfinding defects of
| the growth cones. The lack of a positive correlation between the two
| aspects of growth cone behavior implicates multiple signaling pathways
| downstream of activated Cdc42 controlling filopodial activity and growth
| cone pathfinding, respectively, and demonstrates Cdc42's role as a major
| regulator of subcellular events within the axonal growth cone.
AU|Kim
|M.D.
AU|Chiba
|A.
YR|2001
TI|Growth cone pathfinding and filopodial dynamics are mediated separately by Cdc42 activation.
JR|Bellen, Taylor, 2001
PG|219
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144569	AU 1 Kitamoto	YR 1 2001	TP 1 Abstract	TI 1 Conditional disruption of synaptic transmission induces male-male courtship behavior in Drosophila.	REFM 1 Bellen, Taylor, 2001: 106		
ID|FBrf0144569
TP|abstract
|Drosophila meeting abstract
MABST|It is reported here that the sexual orientatio n of Drosophila males is
| instantaneously altered by disruption of synaptic transmission in selected
| neurons. A temperature-sensitive allele of the Drosophila dynamin gene
| shibire (shi ts1 ) was expressed using the GAL4/ UAS system to rapidly and
| reversibly disrupt synaptic transmission in anatomically defined neurons in
| a temperature-dependent manner. An enhancer-trap GAL4 line C309 directing
| shi ts1 expression in restricted groups of neurons (C309/ UAS-shi ts1 )
| initiated stereotypical precopulatory behavior to ward other mature males
| immediately after a temperature shift from 19�C to 30�C. At the higher
| temperature, groups of C309/ UAS-shi ts1 males formed "courtship chains",
| and demonstrated abnormally high levels of head-to-head interactions. The
| male-male courtship behavior is not attributable to an increased sexual
| attractiveness of transformant males, but rather to their increased sexual
| activity toward other mature males, since C309/ UAS-shi ts1 males also
| courted non-transformant males in isolated pairs at 30�C, but not vice
| versa. The increased sexual activity is specific toward male partners. At
| 30�C, C309/ UAS-shi ts1 males court receptive females less vigorously and
| copulate less efficiently than they do at 19�C. A direct link between male
| -male courtship behavior and synaptic transmission in particular neurons
| allows further exploration as to how distinct neuronal groups are involved
| in the actual manifestation of sexual orientation in Drosophila.
AU|Kitamoto
|T.
YR|2001
TI|Conditional disruption of synaptic transmission induces male-male courtship behavior in Drosophila.
JR|Bellen, Taylor, 2001
PG|106
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144570	AU 1 Kjaerulff et al.	YR 1 2001	TP 1 Abstract	TI 1 In vivo analysis of the function of endophilin.	REFM 1 Bellen, Taylor, 2001: 33		
ID|FBrf0144570
TP|abstract
|Drosophila meeting abstract
MABST|Endophilin was originally isolated in mammalian screens for SH3
| domain-containing proteins. One isoform, endophilin 1, is presynaptic and
| binds via the SH3 domain to dynamin 1 and synaptojanin, two proteins
| strongly implicated in endocytotic retrieval of synaptic vesicles. In
| addition to the SH3 domain, endophilin contains a conserved N-terminal
| domain with membrane lipid-modifying enzymatic activity shown to be
| important for endocytosis of synaptic-like microvesicles in vitro. However,
| the consequences of genetically manipulating endophilin expression in the
| intact synapse have nCould not acquire words on page 107 ot been
| investigated. We are characterizing endophilin (D-endo) function in vivo in
| wild type and mutant Drosophila. A number of P elements have been
| identified that map to the 5'UTR of the D-endo gene. We find that the
| insertions are lethal and that the lethality is due to disruption of the
| D-endo gene. Larvae mutant for the most severe P element insertion, endo 1
| , are sluggish and die as young 3 rd instars. D-endo is only required in
| the nervous system, as pan-neuronal expression of the gene in homozygous
| mutants rescues the lethality associated with the P element insertions.
| D-ENDO message is highly enriched in the nervous system of embryos and 3 rd
| instar larvae. An antibody raised against D-endo detects the protein at
| synaptic boutons of 3 rd instar neuromuscular junctions (NMJs). A
| comprehensive analysis of endo 1 suggests a defect in synaptic vesicle
| endocytosis. Homozygous endo 1 eyes generated with the eyFLP system in
| adult flies show normal morphology but fail to activate postsynaptic (wild
| type) lamina neurons in the brain. EM analysis shows that the number of
| synaptic vesicles is reduced in the endo 1 photoreceptor terminals. The
| uptake of the lipophilic dye FM1-43 in stimulated motor nerve boutons is
| severely reduced in endo 1 NMJs, and the decay seen in controls in the
| evoked junctional potential (EJP) amplitude during tetanic stimulation is
| strongly enhanced. Also, post-tetanic recovery of the EJP is severely
| delayed in endo 1 NMJs. We conclude that while endophilin is not important
| for exocytosis, this protein plays a prominent role in synaptic vesicle
| endocytosis, presumably by maintaining the large pool of synaptic vesicles
| necessary for sustaining neurotransmitter release at physiologically
| relevant firing frequencies.
AU|Kjaerulff
|O.
AU|Verstreken
|P.
AU|Lloyd
|T.L.
AU|Atkinson
|R.A.
AU|Zhou
|Y.
AU|Meinertzhagen
|I.A.
AU|Bellen
|H.J.
YR|2001
TI|In vivo analysis of the function of endophilin.
JR|Bellen, Taylor, 2001
PG|33
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144571	AU 1 Pielage et al.	YR 1 2001	TP 1 Abstract	TI 1 Analysis of kette and klotzchen, two genes affecting midline glial cell migration.	REFM 1 Bellen, Taylor, 2001: 16		
ID|FBrf0144571
TP|abstract
|Drosophila meeting abstract
MABST|The major axon tracts in the embryonic CNS of Drosophila are organized in a
| simple, ladder like pattern. Each neuromere contains two commissures that
| connect the two contra-lateral sides and two longitudinal connectives
| connecting the different neuromeres along the anterior-posterior axis. The
| formation of the commissural tracts occurs in close association with the
| CNS midline glial cells. In the absence of midline glial cells a
| characteristic commissural phenotype develops. In a large-scale phenotypic
| screen we identified more than 20 genes required for midline glial
| differentiation. Work on kl�tzchen and kette will be presented. kl�tzchen
| (klo) mutations affect the formation of cell processes that characterize
| wild type glial cells and lead to a strong fused commissure CNS phenotype.
| We isolated 3 P-element induced klo alleles, all carrying an P-insertion
| within the first intron of the a-spectrin gene. In mutant klo embryos no
| a-spectrin expression can be detected. Furthermore, the klo mutant
| phenotype can be rescued by ubiquitous a-spectrin expression, suggesting
| that klo is allelic to a-spectrin. However, in stark contrast to this
| notion, amorphic a-spectrin mutations do not result in an embryonic CNS
| phenotype. Within the first a-spectrin intron a second ORF was found that
| shares the first non-coding exon with a-spectrin. Using this intron based
| gene we were also able to rescue the klo mutant phenotype. Thus, klo acts
| as a regulator of a-spectrin expression. Experiments addressing the
| molecular mechanism of klo function will be presented. kette mutations
| affect the formation of neuronal cell processes that serve as a monorail
| during midline glial cell migration and thus also lead to a strong fused
| commissure CNS phenotype. kette encodes an evolutionary conserved, membrane
| associated protein implicated in the regulation of the actin cytoskeleton.
| We will present genetic as well as biochemical studies that identified
| kette-interacting genes linking kette function to the regulation of the
| neuronal cytoskeleton.
AU|Pielage
|J.
AU|Bogdan
|S.
AU|Klambt
|C.
YR|2001
TI|Analysis of kette and klotzchen, two genes affecting midline glial cell migration.
JR|Bellen, Taylor, 2001
PG|16
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144573	AU 1 Kokel et al.	YR 1 2001	TP 1 Abstract	TI 1 Isolation of mutations that alter muscle-epidermal attachment.	REFM 1 Bellen, Taylor, 2001: 154		
ID|FBrf0144573
TP|abstract
|Drosophila meeting abstract
MABST|In addition to acting as a guidance receptor controlling commissure choice
| in the CNS, Derailed (Drl) is required for the selection of appropriate
| epidermal attachment sites by developing muscles. In drl mutants, muscles
| 21-23 occasionally bypass their normal attachment sites and instead attach
| to ectopic epidermal cells. This defect is observed in 20% of hemisegments,
| suggesting that other genes are involved in this process. We carried out a
| genetic screen in order to identify these genes, as well as genes involved
| in other aspects of muscle development. We used EMS to mutagenize flies
| expressing lacZ in muscles 21-23 and generated 4000 F2 lines. Mutant
| embryos were screened by whole mount X-gal staining and scored for their
| muscle phenotype. We have identified mutants that appear to have defects in
| founder cell specification, myoblast fusion, myotube migration, and general
| aspects of muscle attachment to epidermal cells. In addition, we have
| isolated five mutants that display specific defects in muscle attachment
| site selection. Two of these enhance both the CNS and muscle phenotypes
| associated with mutations in drl and one has defects in commissure
| formation on its own when homozygous. We are currently analyzing these
| phenotypes in greater detail and have begun to identify the causative genes.
AU|Kokel
|M.
AU|Cua
|D.
AU|Thomas
|J.B.
YR|2001
TI|Isolation of mutations that alter muscle-epidermal attachment.
JR|Bellen, Taylor, 2001
PG|154
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144574	AU 1 Lee and Kolodziej	YR 1 2001	TP 1 Abstract	TI 1 Short stop links F-actin to microtubules during axon extension.	REFM 1 Bellen, Taylor, 2001: 88		
ID|FBrf0144574
TP|abstract
|Drosophila meeting abstract
MABST|Coordination of F-actin and microtubule dynamics is important for cellular
| motility and morphogenesis, but little is known about underlying
| mechanisms. short stop (shot) encodes an evolutionarily conserved,
| neuronally expressed family of rod-like proteins required for sensory and
| motor axon extension in Drosophila melanogaster. We identify Shot isoforms
| that contain N-terminal F-actin and C-terminal microtubule binding domains,
| and that cross-link F-actin and microtubules in cultured cells. Shot's
| F-actin and microtubule binding domains are required in the same molecule
| for axon extension, though the length of the connecting rod domain can be
| dramatically reduced without affecting activity. Shot therefore functions
| as a cytoskeletal cross-linker in axon extension, rather than mediating
| independent interactions with F-actin and microtubules, as observed in
| other cell types. A calcium binding motif located adjacent to the
| microtubule binding domain is also required for axon extension, suggesting
| that intracellular calcium release may regulate Shot activity. These
| results suggest that Shot coordinates regulated interactions between
| F-actin and microtubules critical for neuronal morphogenesis. Furthermore,
| genetic and biochemical interactions with known regulators of F-actin
| polymerization suggest that Shot regulates F-actin polymerization during
| axon extension.
AU|Lee
|S.
AU|Kolodziej
|P.
YR|2001
TI|Short stop links F-actin to microtubules during axon extension.
JR|Bellen, Taylor, 2001
PG|88
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144575	AU 1 Kraut and Zinn	YR 1 2001	TP 1 Abstract	TI 1 Novel findings from an overexpression screen: Vesicle trafficking in pathfinding and Robo in sense organ formation.	REFM 1 Bellen, Taylor, 2001: 221		
ID|FBrf0144575
TP|abstract
|Drosophila meeting abstract
MABST|An over/ misexpression screen was carried out using the UAS-carrying EP
| lines of P. Rorth (PNAS [1996] 93( 22): 12418-22), with the goal of
| identifying genes which when expressed at high levels in the nervous system
| would lead to motorneuron pathfinding and or synaptogenesis errors.
| Phenotypes produced by overexpression of genes via the elav-Gal4 driver
| were screened by observation of the motorneuron innervation pattern in live
| larvae co-expressing GFP in all neurons (Kraut et al., Curr Biol [2001] 20;
| 11( 6): 417-30). Over 70 genes were identified in the screen, about half of
| which were novel (i. e. having no published mutant phenotype). Among the
| known pathfinding genes identified in the screen was robo2, a transmembrane
| receptor of the Ig family. Robo2 is expressed on axons, and is known for
| its role in regulating midline crossing and longitudinal pathway patterning
| of the CNS via the ligand slit (reviewed by Rusch &amp; Van Vactor, Cell
| [2000] 28: 637-640). We identified a novel function of robo2 in specifying
| larval sense organ fates. Overexpression of this molecule in all neurons
| leads to the production of excess chordotonal organs in the PNS. Loss of
| function of robo2 and related genes robo1 and robo3 also affects sense
| organ formation. All three robos are expressed in larval sense organs. Of
| the novel genes identified in the screen, many appear to be involved in
| endocytosis/ membrane trafficking. Two of these that will be discussed are
| Beached, a relative of the human Chediak-Higashi Syndrome gene and
| Gartenzwerg, an Arabidopsis GNOM homolog.
AU|Kraut
|R.
AU|Zinn
|K.
YR|2001
TI|Novel findings from an overexpression screen: Vesicle trafficking in pathfinding and Robo in sense organ formation.
JR|Bellen, Taylor, 2001
PG|221
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144576	AU 1 Krishnan et al.	YR 1 2001	TP 1 Abstract	TI 1 Circadian control of peripheral and central clock outputs in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 107		
ID|FBrf0144576
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila, circadian clock function has been intensely studied using
| molecular and genetic techniques. However, physiological aspects of
| circadian oscillators have received less attention than the core
| timekeeping mechanism. We have characterized a physiological output of the
| clock using electroantennogram recordings (EAGs) to examine the circadian
| regulation of olfaction. Previously, we presented data showing that
| olfactory rhythms of wild type flies entrained to light -dark cycles peaked
| during the middle of the subjective night, while non functional mutants per
| and tim abolish this rhythm. In addition, this rhythm in olfactory
| responses requires the function of peripheral oscillators. We have used
| this output to study the function of cryptochrome in peripheral
| oscillators. CRYPTOCHROME was originally identified as a circadian
| photoreceptor for the central (i. e. locomotor activity) oscillator in
| Drosophila. Although a mutant allele of cryptochrome, cry b , is defective
| in light entrainment, central oscillator function is normal during and
| after light -dark entrainment. We now show that olfactory rhythms in cry b
| mutants are abolished. This effect of cry b on olfactory rhythms persists
| even when flies are entrained to temperature cycles in the complete absence
| of light; a condition which supports central oscillator function. These
| results demonstrate a photoreceptor-independent role for CRY in the
| periphery and imply fundamental differences between central and peripheral
| oscillator mechanisms in Drosophila. We also observed that temperature
| entrainment of wild type flies resulted in olfactory rhythms that are
| antiphase to those seen in light entrained flies. We are currently
| investigating the state of molecular oscillators in peripheral and central
| tissues in response to different light-dark and temperature entrainment paradigms.
AU|Krishnan
|B.
AU|Dryer
|S.E.
AU|Hardin
|P.E.
YR|2001
TI|Circadian control of peripheral and central clock outputs in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|107
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144577	AU 1 Kuchinke et al.	YR 1 2001	TP 1 Abstract	TI 1 Fly homologs of ProSAP and MAGI are putative scaffolding molecules at larval neuromuscular junctions.	REFM 1 Bellen, Taylor, 2001: 222		
ID|FBrf0144577
TP|abstract
|Drosophila meeting abstract
MABST|A tight protein network serves the synaptic clustering of ion channels, cell
| adhesion molecules and cytoplasmic signalling molecules. Membrane
| associated guanylate kinases (MAGUKs) such as DLG constitute one important
| family of clustering molecules. Recent studies on mammalian CNS synapses
| have led to the identification of novel scaffolding proteins, including
| isoforms of ProSAP/ Shank and MAGI/ S-SCAM. For both proteins several
| interacting partners have been identified and some of them are shared by
| DLG-like MAGUKs. This suggests that MAGUK-, ProSAP-and MAGI proteins are
| functionally coupled and/ or exert redundant functions. We have cloned
| cDNAs encoding Drosophila homologues of ProSAP and MAGI and raised antisera
| against either protein. Immunofluorensce studies reveal that both proteins
| are expressed in different subpatterns at type I boutons of larval
| neuromuscular junctions. Preliminary data suggest that synaptic
| localization of both proteins does not depend on DLG. Our aim is to
| characterize the role of D-ProSAP and D-MAGI during synapse formation,
| development and plasticity. For this we have started to gener ate 1)
| mutants by excision of nearby P-elements and 2) transgenic flies that allow
| for targeted expression of GFP-tagged and non-tagged D-ProSAP and D-MAGI.
| Updated results from these experiments will be presented.
AU|Kuchinke
|U.
AU|Bockers
|T.M.
AU|Budnik
|V.
AU|Gundelfinger
|E.D.
AU|Thomas
|U.
YR|2001
TI|Fly homologs of ProSAP and MAGI are putative scaffolding molecules at larval neuromuscular junctions.
JR|Bellen, Taylor, 2001
PG|222
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144578	AU 1 Kuppers et al.	YR 1 2001	TP 1 Abstract	TI 1 Regulation of GABA in the developing CNS of Drosophila embryos.	REFM 1 Bellen, Taylor, 2001: 223		
ID|FBrf0144578
TP|abstract
|Drosophila meeting abstract
MABST|In the developing CNS of vertebrates, GABAergic synapses seem to develop
| before glutamatergic synapses. GABA-mediated giant depolarising potentials
| are thought to be required for correct circuit formation. We are interested
| in mechanisms underlying synapse development in Drosophila embryos. Here we
| investigate the regulation of GABA expression in the developing Drosophila
| CNS. Induction of GABA is a slow process starting at late stage 16, thus at
| a time when first electrical activity has been reported for central
| neurons. Interestingly, presence of the GABA synthetising enzyme Gad from
| about stage 15 onwards has been reported. Furthermore, even strong Gal4/
| Uas-mediated expression of Gad protein does not cause significantly earlier
| GABA induction although, at later stages, severe ectopic expression of GABA
| can be seen. We conclude that Gad activity is posttranslationally
| regulated. A potential posttranslational inhibitory effect on
| GABA-induction can also be observed in primary cell culture upon increase
| of the potassium concentration in the culture medium. This inhibition can
| clearly override Gal4/ Uas-induced Gad activity. However, in mature cell
| cultures a shift to lower potassium concentrations for only one hour is
| sufficient to obtain strong GABA induction. Since a shift of one hour is
| short enough to apply even toxic substances to the cultured cells we can
| now use this experimental scheme in order to investigate mechanisms
| potentially mediating the induction of GABA. Such analyses can be combined
| with mutant analyses in the embryonic CNS and primary cultures. So far we
| have mainly focussed on calcium mediated pathways since GABA induction
| nicely correlates with the reported timing of calcium currents in the
| developing CNS. This work is supported by the Deutsche
| Forschungsgemeinschaft (PR605/ 1-2) and the Volkswagen-Foundation (I/ 75 471).
AU|Kuppers
|B.
AU|Sanchez-Soriano
|N.
AU|Prokop
|A.
YR|2001
TI|Regulation of GABA in the developing CNS of Drosophila embryos.
JR|Bellen, Taylor, 2001
PG|223
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144579	AU 1 Kumar and Moses	YR 1 2001	TP 1 Abstract	TI 1 Testing the developmental capacity of the eye imaginal disc.	REFM 1 Bellen, Taylor, 2001: 132		
ID|FBrf0144579
TP|abstract
|Drosophila meeting abstract
MABST|The specification of the compound eye is under the control of seven nuclear
| factors that include the homolog of Pax6. Recently we have shown that
| Epidermal Growth Factor Receptor and Notch signaling cascades lie upstream
| of these eye specification genes. Alterations in the signaling levels of
| these pathways within the eye imaginal disc leads to the transdetermination
| of the eye into an antenna, a novel homeotic transformation that is not
| predicted by either phenotypes of existing homeotic mutants or disc
| transplantation experiments. We are interested in further determining the
| developmental capacity of the eye imaginal disc. Using the UAS/ GAL4 system
| we have expressed genes that normally control the development of other
| appendages within the eye disc thus constructing a series of in vivo
| competition assays in which the eye imaginal disc must choose between an
| eye fate and that of other imaginal discs. We will describe the results
| that we have obtained so far. Several laboratories have shown that the
| misexpression of the eye specification genes results in the formation of
| ectopic eyes. However, retinal development in other imaginal discs is
| restricted and it has been demonstrated that the signaling molecules
| Decapentaplegic and Hedgehog are crucial for the formation of ectopic eyes.
| We have misexpressed eyeless within the wing imaginal disc using a large
| collection of GAL4 drivers and have observed several interesting patterns
| that shed new light on the ability of other imaginal discs to develop
| ectopic eyes. We will describe our preliminary results.
AU|Kumar
|J.P.
AU|Moses
|K.
YR|2001
TI|Testing the developmental capacity of the eye imaginal disc.
JR|Bellen, Taylor, 2001
PG|132
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144580	AU 1 Kurusu et al.	YR 1 2001	TP 1 Abstract	TI 1 Axonal pioneering and layer formation of the mushroom bodies in the early Drosophila brain: Importance of Fasciclin II and mushroom body deranged.	REFM 1 Bellen, Taylor, 2001: 191		
ID|FBrf0144580
TP|abstract
|Drosophila meeting abstract
MABST|Mushroom bodies (MBs) are the centers for olfactory associative learning and
| elementary cognitive functions in the neopteran insect brain. In order to
| understand the cellular and genetic processes that control the early
| development of MBs, we performed high-resolution neuroanatomical studies of
| the embryonic and post-embryonic MBs of the Drosophila brain using various
| axonal and cell type specific markers. We show that, at the mid embryonic
| stages, the pioneer axons of the embryonic MB initially tracts extend along
| a group of cells that express Fasciclin II (Fas II ). In the subsequent
| stages, the MB axons converge at the lateral protocerebral tract and
| further extend beyond the major tract to form the distal part of the
| embryonic peduncle, which makes a sharp medial turn at the border of the
| proto-and deuterocerebrum anlagen and forms the embryonic medial lobe. By
| the hatching of first instar lavae, discrete layers are developed in the
| lobes and peduncles as early as in the first instar larvae and are
| maintained up to the onset of pupation, when the axonal projections of the
| MBs undergo massive reorganization. Genetic analyses show that the
| development of the lobes and the formation of the underlying layer
| structures of the larval MBs is strongly perturbed by hypomorphic mutations
| of Fas II . Furthermore, similar yet more profound developmental defects
| are caused by the mutation of mushroom body deranged, which has been
| identified as an anatomical MB mutation in the adult brain. Given that the
| MBs at the early larval instars consist of only the g? group axonal
| projections, these results uncover unexpected underlying complexity of the
| larval MBs and demonstrate the importance of Fas II and mbd to the early
| development of the functional compartments of the larval and adult MBs.
AU|Kurusu
|M.
AU|Masuda-Nakagawa
|L.
AU|Furukubo-Tokunaga
|K.
YR|2001
TI|Axonal pioneering and layer formation of the mushroom bodies in the early Drosophila brain: Importance of Fasciclin II and mushroom body deranged.
JR|Bellen, Taylor, 2001
PG|191
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144581	AU 1 Kuzin et al.	YR 1 2001	TP 1 Abstract	TI 1 nerfin-1, a member of a conserved Zn-finger gene subfamily, is required for proper neuronal cell fate specification.	REFM 1 Bellen, Taylor, 2001: 155		
ID|FBrf0144581
TP|abstract
|Drosophila meeting abstract
MABST|Developing nervous systems employ integrated regulatory networks to generate
| specific cell-lineages and, ultimately, to produce unique cellular
| phenotypes. Our efforts are directed at understanding the molecular events
| that control cell-identity decisions during CNS development. We have
| identified a new Zn-finger gene, nerfin-1 (nervous fingers) from a cDNA
| library screen for genes expressed during CNS neuroblast (NB) lineage
| development 1 . nerfin-1 belongs to a conserved Zn-finger gene subfamily,
| with known human, mouse and nematode cognates. RNAi studies reveal that
| Nerfin-1 is essential for proper lineage development in both the CNS and
| PNS. In addition to the aberrant expression of multiple neuronal identity
| regulators, RNAi experiments indicate that nerfin-1 may also be required
| for proper axonal outgrowth. During embryonic CNS development, nerfin-1
| mRNA expression shifts from early delaminating NBs to most, if not all,
| ganglion mother cells. However, immunolocalization studies reveal that
| Nerfin-1 protein accumulates only in the nucleus of neuronal precursor
| cells (both CNS and PNS) that are poised to undergo a single final division
| that generates neurons. Interestingly, after this final division, Nerfin-1
| exits the nucleus and is transported into growing axons. To determine the
| functional significance of its restricted expression dynamics, we have
| targeted Nerfin -1 misexpression to different NB lineage temporal/ spatial
| windows of development. Misexpression via prospero-and elav-Gal4 drivers
| induces embryonic lethality. An array of lineage markers will be employed
| to study the effects of Nerfin-1 misexpression on CNS development. To
| further investigate the role of nerfin-1, we are now generating stable
| loss-of-function mutations and transformant lines that express nerfin-1/
| GFP chimeric proteins. Initially, these tools will be employed to determine
| if nerfin-1 is involved in the temporal regulation of neural lineage
| development. More specifically, we will determine if nerfin-1 function is
| required for precursor cells and/ or their nascent neurons to exit the cell
| cycle and undergo terminal differentiation. 1. Stivers et al., Mechanisms
| of Development, 97: 205-210, (2000)
AU|Kuzin
|A.
AU|Stivers
|C.
AU|Brody
|T.
AU|Odenwald
|W.F.
YR|2001
TI|nerfin-1, a member of a conserved Zn-finger gene subfamily, is required for proper neuronal cell fate specification.
JR|Bellen, Taylor, 2001
PG|155
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144582	AU 1 Lai et al.	YR 1 2001	TP 1 Abstract	TI 1 Neuralized is a ubiqutin ligase that promotes degradation of Delta.	REFM 1 Bellen, Taylor, 2001: 15		
ID|FBrf0144582
TP|abstract
|Drosophila meeting abstract
MABST|The Notch (N) pathway is a conserved signal transduction module that is
| essential for the proper execution of a wide variety of developmental
| processes. The Drosophila gene neuralized (neur) is required in many,
| although not all, settings of N pathway function. However, its role in the
| pathway has long been elusive. Our previous phenotypic characterization of
| neur showed that neur functions autonomously during adult peripheral
| neurogenesis and eye development, indicating that it is important in
| reception of the N signal. Neur has been highly conserved over evolution
| and consists of two copies of a novel domain (Neuralized Homology Repeat,
| NHR) followed by a C-terminal RING finger. The full-length protein induced
| gain-of-function phenotypes when activated at lower levels, but caused
| loss-of-function phenotypes when activated at much higher levels. In
| contrast, a truncated form lacking the RING finger (Neur D RF) had potent
| dominant-negative activity. These results suggested that Neur might
| function as part of a multi-protein complex. Finally, we determined that
| epitope-tagged Neur is associated with the plasma membrane. We have gone on
| to demonstrate that Neur displays genetic interactions with an E2 ubiquitin
| conjugating enzyme (UbcD1) and that the Neur RING finger exhibits ubiquitin
| ligase activity in vitro. The Notch ligand Delta (Dl) is a possible target
| of Neur activity, since Dl dominantly modifies Neur misexpression
| phenotypes in multiple developmental settings. Several lines of evidence
| indicate that this is the case. Mutant clonal analysis in the eye reveals
| that neur negatively regulates accumulation of Dl. In vivo assays
| demonstrate that ectopic Neur targets Dl for rapid internalization and
| degradation in a RING finger -dependent manner. Finally, Neur and Dl exist
| in a physical complex. Collectively, our data suggest that the function of
| Neur in the N pathway may be to ubiquitinate Dl at the plasma membrane, an
| event that leads to endocytosis and degradation of Dl.
AU|Lai
|E.C.
AU|Deblandre
|G.
AU|Kintner
|C.
AU|Rubin
|G.M.
YR|2001
TI|Neuralized is a ubiqutin ligase that promotes degradation of Delta.
JR|Bellen, Taylor, 2001
PG|15
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144583	AU 1 Rohrbaugh et al.	YR 1 2001	TP 1 Abstract	TI 1 Suppressor of hairless-mediated activation of Yan expression is antagonized by the ETS protein pointed in the Drosophila eye.	REFM 1 Bellen, Taylor, 2001: 133		
ID|FBrf0144583
TP|abstract
|Drosophila meeting abstract
MABST|During early Drosophila eye development, progenitor cells remain
| undifferentiated until they receive inductive signal from the activated
| receptor tyrosine ki nase such as DER. Earlier work has demonstrated that
| Yan, an ETS-domain transcriptional repressor, normally blocks cellular
| potential for specification and differentiation, and Yan-mediated
| inhibition can be overcome by activated RTK signaling. A key component of
| the RTK pathway, MAP kinase, targets Yan for phosphorylation and
| destabilization. Yan protein is highly expressed in progenitor cells but
| not in differentiating cells. How yan expression is established in the
| progenitor cells? Notch is a cell surface receptor that is activated
| through direct interaction with its ligand produced by neighboring cells.
| Notch signaling plays multiple roles throughout the eye development, one of
| which is to prevent progenitor cells from neural differentiation. Our
| results indicate that yan is a direct target of the Suppressor of Hairless
| [Su( H)] protein. We show that Su( H) binds specifically to an eye-specific
| yan enhancer, and both the Su( H)-binding sites in the enhancer and the Su(
| H) gene are essential for yan enhancer activation. In contrast, the ETS
| protein Pointed is both essential and sufficient to block the yan enhancer
| function. Thus, opposition between Notch and RTK signaling can be mediated
| through a tissue-specific enhancer for cell fate control.
AU|Rohrbaugh
|M.
AU|Ramos
|E.
AU|Nguyen
|D.
AU|Price
|M.
AU|Wen
|Y.
AU|Lai
|Z.C.
YR|2001
TI|Suppressor of hairless-mediated activation of Yan expression is antagonized by the ETS protein pointed in the Drosophila eye.
JR|Bellen, Taylor, 2001
PG|133
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144584	AU 1 Landgraf and Bate	YR 1 2001	TP 1 Abstract	TI 1 Patterning of dendritic arbors in the embryonic CNS of Drosophila.	REFM 1 Bellen, Taylor, 2001: 224		
ID|FBrf0144584
TP|abstract
|Drosophila meeting abstract
MABST|In the Drosophila embryo, the development of the ventral nerve cord appears
| to be highly and reproducibly structured. By studying the mechanisms that
| pattern the ventral nerve cord and thus position the individual components
| of the neural circuitry within it we are hoping to begin to understand some
| of the underlying principles that govern the assembly of neural networks.
| To this end, we have characterised the central projections of the abdominal
| motorneurons in the Drosophila embryo, which are readily accessible by
| retrograde labelling (using the lipophilic tracers DiI, DiD and DiA). The
| dendritic arbors of motor neurons are confined to the dorsal neuropil.
| Double labelling of motor neurons reveal that the neuropil of each
| neuromere is subdivided from anterior to posterior into several dendritic
| domains, and that each such dendritic domain is occupied by the dendritic
| arbors of a distinct set of motor neurons. Moreover, we find a correlation
| between these dendritic domains in the neuropil and the position of the
| corresponding motor neuron target muscles in the periphery: each dendritic
| domain is occupied by the dendritic arbors of motor neurons with
| functionally related target muscles (by position and orientation in the
| muscle field). We are currently investigating the mechanisms that underlie
| the somatotopic patterning of motor neuron dendritic arbors in the neuropil.
AU|Landgraf
|M.
AU|Bate
|M.
YR|2001
TI|Patterning of dendritic arbors in the embryonic CNS of Drosophila.
JR|Bellen, Taylor, 2001
PG|224
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144585	AU 1 Laurencon et al.	YR 1 2001	TP 1 Abstract	TI 1 dRFX is essential to non-visual sensory perception in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 134		
ID|FBrf0144585
TP|abstract
|Drosophila meeting abstract
MABST|dRFX is expressed in the peripheral nervous system and more precisely in the
| type I sensory neurons. It is also detected in a restricted number of brain
| cells throughout development and in spermatids of adult males. We have
| isolated different dRFX alleles and show that mutants are mostly homozygous
| lethal. Death occurs during larval stages, where larvae do not respond to
| attractive or repulsive chemicals. The rare adult survivors present acute
| uncoordination defects. We also show that these mutations eliminate
| transduction in Drosophila mechanosensory organs. We are currently
| analyzing cellular defects of the cilia in these sensory neurons by
| electron microscopy. dRFX is thus essential for sensory neuron function in
| Drosophila melanogaster. This transcription factor is homologous to CeRFX/
| daf-19 in C. elegans which has been shown to be involved in cilium
| differentiation of sensory neurons in the nematode. These data thus imply
| an evolutionary conservation of their function in ciliogenesis control.
AU|Laurencon
|A.
AU|Dubruille
|R.
AU|Coulon
|M.
AU|Couble
|P.
AU|Shishido
|E.
AU|Kernan
|M.
AU|Durand
|B.
YR|2001
TI|dRFX is essential to non-visual sensory perception in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|134
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144586	AU 1 Le Gall et al.	YR 1 2001	TP 1 Abstract	TI 1 Roles of Notch/Abl/Dab and Notch/Su(H) signaling pathways in Drosophila axon patterning.	REFM 1 Bellen, Taylor, 2001: 225		
ID|FBrf0144586
TP|abstract
|Drosophila meeting abstract
MABST|The transmembrane receptor Notch is a key player in neuronal development: it
| both determines neuron cell fate and directs axon patterning. The best
| understood Notch signaling pathway involves activation of the transcription
| factor Suppressor of Hairless (Su( H)). However, we have previously shown
| that Notch also interacts genetically with the Abl tyrosine kinase and
| biochemically with the Abl modifier Disabled (Dab) defining a new Notch
| signaling pathway independent of Su( H). To determine the relative
| contributions of the Su( H) and the Abl/ Dab pathways in Notch dependent
| axon patterning, we have used two complementary approaches: 1) systematic
| mutation of Notch to identify the domains that control axon patterning and
| 2) isolation and analysis of a Dab mutant. Our data show that the Ram and
| Ank domains of Notch are required for the control of axon patterning
| whereas a large intracellular domain of Notch, which regulates the Jnk
| pathway, is dispensable. We have also identified Su( H) and Dab binding
| sites in the Notch protein and will analyze the phenotypes of mutants
| lacking these sites. To further characterize the Notch/ Abl/ Dab pathway,
| we have isolated a mutant of Dab. Dab mutant embryos present unpredicted
| phenotypes. First, the ventral nerve cord fails to condense during late
| stages of embryogenesis. Second, there are a variety of axon guidance
| errors where particular nerve tracts fail to extend to their normal targets
| and/ or are misrouted to incorrect locations. Finally the normal pattern of
| muscle positioning is frequently disturbed.
AU|Le Gall
|M.
AU|Gates
|M.
AU|DeMattei
|C.
AU|Giniger
|E.
YR|2001
TI|Roles of Notch/Abl/Dab and Notch/Su(H) signaling pathways in Drosophila axon patterning.
JR|Bellen, Taylor, 2001
PG|225
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144589	AU 1 Wang et al.	YR 1 2001	TP 1 Abstract	TI 1 Drosophila Dscam is required for divergent segregation of sister branches and suppresses ectopic bifurcation of axons within the mushroom bodies.	REFM 1 Bellen, Taylor, 2001: 168		
ID|FBrf0144589
TP|abstract
|Drosophila meeting abstract
MABST|Axon bifurcation results in the formation of sister branches, and divergent
| segregation of the sister branches is essential for efficient innervation
| of multiple targets. From a genetic mosaic screen, we find that a lethal
| mutation in the Drosophila Down syndrome cell adhesion molecule (Dscam)
| specifically perturbs segregation of axonal branches in the mushroom bodies
| (MBs). Single axon analysis further reveals that Dscam mutant axons
| generate additional branches, which randomly segregate among the available
| targets. Moreover, when only one target remains, branching is suppressed in
| wild-type axons while Dscam mutant axons still form multiple branches at
| the original bifurcation point. Taken together, we conclude that Dscam
| controls axon branching and guidance such that a neuron can innervate
| multiple targets with minimal branching. In addition, phenotypic analysis
| of mosaic MBs reveals that Dscam mutant neurons can alter the projections
| of other wild-type neurons within the same MB. Analysis of such non-cell
| autonomous effects sheds new light on how the insect olfactory learning and
| memory center acquires its normal projection patterns during development.
AU|Wang
|J.
AU|Zugates
|C.T.
AU|Liang
|I.H.
AU|Lee
|C.H.J.
AU|Lee
|T.
YR|2001
TI|Drosophila Dscam is required for divergent segregation of sister branches and suppresses ectopic bifurcation of axons within the mushroom bodies.
JR|Bellen, Taylor, 2001
PG|168
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144590	AU 1 Lee et al.	YR 1 2001	TP 1 Abstract	TI 1 N-cadherin and Dlar mutants, isolated by behavioral screens, exhibit R7 targeting defects.	REFM 1 Bellen, Taylor, 2001: 2		
ID|FBrf0144590
TP|abstract
|Drosophila meeting abstract
MABST|We have conducted visual behavioral screens in Drosophila to study neuronal
| connectivity. To isolate mutations affecting photoreceptor cells (R-cells)
| cell-autonomously, we employ a genetic method to generate mosaic animals
| whose retina alone were homozygous for randomly mutagenized chromosome.
| These mosaic animals were then subjected to two behavioral tests: an
| optomotor assay to assess R1-R6 function and a UV/ VIS light choice test to
| probe R7 connectivity. We isolated 390 mutants (including ~60 loci with
| multiple alleles) that display defective optomotor response. Among these,
| we identified 7 loci, including N-cadherin (Ncad) and Drosophila receptor
| tyrosine phosphatase LAR (Dlar), that also failed the UV/ VIS test.
| Histological analyses revealed severe defects of R7 connectivity resulting
| from loss of Ncad or Dlar function in the retina, in congruence with the
| observed behavioral deficit. To further analyze the roles of Ncad and Dlar
| in R7 target selection, we developed a genetic method to generate single
| mutant R7 axons surrounded by largely wild-type R-cell afferents and a
| wild-type target. R7 axons lacking Dlar or Ncad mistarget to the
| R8-recipient layer. Developmental analysis indicated that target selection
| of R7 involves two consecutive processes: initial target recognition and
| stabilization of R7-target interaction. While Ncad likely takes part in
| both processes, Dlar is only required for the second process. Dlar mutant
| R7 axons project to the correct target initially but fail to remain at the
| R7-recipient layer later, suggesting Dlar's function in stabilizing
| R7-target interaction. We propose that Dlar regulates R7 targeting by
| modulating Ncad-mediated adhesion.
AU|Lee
|C.H.
AU|Clandinin
|T.R.
AU|Herman
|T.
AU|Lee
|R.
AU|Ovasapyan
|S.
AU|Zipursky
|L.
YR|2001
TI|N-cadherin and Dlar mutants, isolated by behavioral screens, exhibit R7 targeting defects.
JR|Bellen, Taylor, 2001
PG|2
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144588	AU 1 Lee et al.	YR 1 2001	TP 1 Abstract	TI 1 The vesicular Ach transporter regulates fast excitatory cholinergic transmission in Drosophila neurons.	REFM 1 Bellen, Taylor, 2001: 34		
ID|FBrf0144588
TP|abstract
|Drosophila meeting abstract
MABST|The vesicular acetylcholine transporter (VAChT) packages neurotransmitter
| acetylcholine (ACh) into synaptic vesicles. The VAChT gene was first
| identified in C. elegans, and subsequently in Topedo, mammals and
| Drosophila on the basis of sequence homology. However, its physiological
| role in the central synaptic transmission is not well characterized. In
| this study we have investigated the role of VAChT in regulating fast
| excitatory cholinergic transmission between Drosophila neurons using three
| different approaches: pharmacology, genetic mutants, and RNA interference.
| First, we report that a specific VAChT blocker, vesamicol (10 m M, 24 hr
| pre-incubation), completely eliminated cholinergic miniature excitatory
| postsynaptic currents (mEPSCs). Second, neurons prepared from embryos
| homozygous for 2 different mutant alleles of the Vacht gene (Vacht 1 and
| Vacht 2 ), exhibited significant reductions in the incidence, frequency,
| and amplitude of the cholinergic mEPSCs. These alterations are specific to
| cholinergic transmission since there was no difference in the incidence or
| mean amplitude of miniature inhibitory postsynaptic currents (mIPSCs)
| mediated by GABA. Further, expression of the wild-type Vacht allele in
| Vacht 1 mutant flies partially rescued the altered cholinergic phenotype.
| Finally, introduction of 641bp double-strand RNA (~ 40nM, 2 day incubation)
| to wild-type neuronal cultures resulted in reduction in both incidence and
| frequency of mEPSCs (&gt; 80%). Together, these data demonstrate that the
| VAChT gene is important in regulating transmission at fast excitatory
| cholinergic synapses in Drosophila neurons. (Supported by NIH grant NS27501
| to DOD and NSF grant IBN-9723216 to TK).
AU|Lee
|D.
AU|O'Dowd
|D.K.
AU|Kitamoto
|T.
YR|2001
TI|The vesicular Ach transporter regulates fast excitatory cholinergic transmission in Drosophila neurons.
JR|Bellen, Taylor, 2001
PG|34
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144587	AU 1 Lee et al.	YR 1 2001	TP 1 Abstract	TI 1 hyperplastic discs is required to regulate the timing and pattern of differentiation in the eye imaginal disc.	REFM 1 Bellen, Taylor, 2001: 135		
ID|FBrf0144587
TP|abstract
|Drosophila meeting abstract
MABST|Differentiation in the eye imaginal disc begins in third instar at the
| posterior midline of the disc and proceeds towards the anterior. The
| Hedgehog (Hh) signal is essential for the timing and patterning of this
| process: cells respond to Hh by producing the diffusable signal
| Decapentaplegic (Dpp) and by differentiating into photoreceptor neurons,
| which themselves produce Hh, thus propagating a wave of differentiation. In
| a mosaic screen for mutations affecting differentiation in the eye, we
| isolated several alleles of hyperplastic discs (hyd), which encodes an E3
| ubiquitin ligase of the HECT family. Clones of hyd mutant cells in the eye
| differentiate prematurely and trigger nonautonomous differentiation and
| overgrowth in surrounding wild type tissue; the clones themselves grow
| poorly and are usually lost from the adult eye. hyd mutant clones
| ectopically express hh and dpp independently of their normal control
| mechanisms. hyd mutant clones in other imaginal discs also show ectopic hh
| and dpp expression, but grow to a larger size than eye clones. Hyd is
| likely to cause the degradation or processing of at least one negative
| regulator of an early step in photoreceptor differentiation. We are
| currently exploring the mechanism by which Hyd represses hh and dpp expression.
AU|Lee
|J.D.
AU|Benlali
|A.
AU|Amanai
|K.
AU|Shearn
|A.
AU|Treisman
|J.
YR|2001
TI|hyperplastic discs is required to regulate the timing and pattern of differentiation in the eye imaginal disc.
JR|Bellen, Taylor, 2001
PG|135
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144591	AU 1 Leiserson and Keshishian	YR 1 2001	TP 1 Abstract	TI 1 Elucidating the PF kinase signaling pathway and its role in glial ensheathment of axons in larval nerves.	REFM 1 Bellen, Taylor, 2001: 226		
ID|FBrf0144591
TP|abstract
|Drosophila meeting abstract
MABST|The larval abdominal nerves are a promising system for uncovering molecular
| events that mediate the glial ensheathment of axons. These nerves are made
| up of just three cellular components: (1) centrally located axons, (2)
| glial cells that wrap the axons, and (3) perineurial cells that form the
| most superficial layer. As a start toward learning the molecular mechanisms
| that give rise to this structure, we have characterized the fray gene,
| which has a striking mutant phenotype in the peripheral nerves. fray
| mutants have glial wrapping defects: glia extend processes, but in extreme
| cases these processes completely fail to wrap or even associate with the
| axons. By contrast, the axons and perineurial cells appear essentially
| normal, suggesting a glial-specific role for fray. Consistent with this
| idea, expression of a fray cDNA in the ensheathing glia rescued the nerve
| phenotype. While fray has a glial-specific function inside the nerves, fray
| also functions at other times and places during development. Sequence
| analysis revealed that fray encodes a Ser/ Thr kinase closely related to
| five other proteins, including two predicted human homologs and a
| previously characterized rat protein, PASK. These proteins define a new
| family of kinases, termed the PF kinases, which share an N-terminal
| catalytic domain and two C-terminal regions of homology. The catalytic
| domain is distantly related to PAK, but outside this domain PF kinases
| share no homology to PAK or any other known proteins. PAKs have been
| implicated in transducing signals from small GTPases, such as Rac and
| Cdc42, that result in changes in the cytoskeleton. The role of PAKs in the
| cytoskeleton is intriguing, given that fray mutant glial cells show
| aberrant morphology, but the signaling pathway mediated by Fray and other
| PF kinases is unknown, and presumably differs from PAK-mediated signaling.
| We have undertaken molecular and genetic screens using fray to identify
| other components of the PF kinase signaling pathway. Results from these
| screens will be presented.
AU|Leiserson
|W.M.
AU|Keshishian
|H.
YR|2001
TI|Elucidating the PF kinase signaling pathway and its role in glial ensheathment of axons in larval nerves.
JR|Bellen, Taylor, 2001
PG|226
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144592	AU 1 Lim et al.	YR 1 2001	TP 1 Abstract	TI 1 Wingless signaling in undifferentiated cells of the eye disc is essential for long-range ommatidial planar polarity.	REFM 1 Bellen, Taylor, 2001: 4		
ID|FBrf0144592
TP|abstract
|Drosophila meeting abstract
MABST|The adult eye of Drosophila consists of approximately 800 ommatidia, each of
| which contains eight photoreceptor cells arranged in an asymmetric
| trapezoidal pattern. Photoreceptor clusters in the dorsal and ventral
| domains of the eye show mirror-symmetric pattern of planar polarity. It has
| been shown that genes in the wingless (wg) pathway such as dishevelled
| (dsh) and armadillo (arm) act in both autonomous and non-autonomous manners
| to establish the planar polarity in the eye. This raises a question how
| these genes function in both local and long-range signaling. To address
| this question, we investigated the role of wg pathway genes in patterning
| the planar polarity in the developing eye disc. We show that the changes in
| the polarity pattern due to loss of Dsh or Arm are strikingly different
| depending on the position of mutant clones in the disc. Interestingly,
| non-autonomous long-range signaling is mediated by a population of
| undifferentiated cells whose nuclei remain in the basal region of the disc
| during photoreceptor recruitment. Clones of cells with ectopic expression
| of Dsh or Arm in the basal layer do not intermingle well with surrounding
| cells. Furthermore, these ectopic clones induce non-autonomous long-range
| polarity changes in the apical photoreceptor clusters. These results
| suggest that the border of Dsh + and Dsh -cells in the basal region may be
| critical for the formation of a dorsoventral compartment boundary. Finally,
| we show that Bar expression is induced at the periphery of ectopic Dsh +
| clones and is also required for non-autonomous planar polarity signaling.
| This suggests that Bar is an important mediator of Wg signaling in this
| process. In summary, we propose a novel function of undifferentiated cells
| at the basal region of the disc in determining the position of the equator
| and planar polarity signaling.
AU|Lim
|J.
AU|Cho
|K.O.
AU|Choi
|K.W.
YR|2001
TI|Wingless signaling in undifferentiated cells of the eye disc is essential for long-range ommatidial planar polarity.
JR|Bellen, Taylor, 2001
PG|4
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144593	AU 1 Lin et al.	YR 1 2001	TP 1 Abstract	TI 1 Photic signaling by cryptochrome in the Drosophila circadian system.	REFM 1 Bellen, Taylor, 2001: 108		
ID|FBrf0144593
TP|abstract
|Drosophila meeting abstract
MABST|Oscillations of the period (per) and timeless (tim) gene products are an
| integral part of the feedback loop that underlies circadian behavioral
| rhythms in Drosophila. Resetting of this loop in response to light requires
| the putative circadian photoreceptor cryptochrome (CRY). We dissected the
| early events in photic resetting by determining the mechanisms underlying
| the CRY response to light and by investigating the relationship between CRY
| and the light-induced ubiquitination of the TIM protein. In response to
| light, CRY is degraded by the proteasome through a mechanism that requires
| electron transport. Various CRY mutant proteins fail to be degraded and
| suggest that an intramolecular conversion is required for this light
| response. Light-induced TIM ubiquitination precedes CRY degradation and is
| increased when electron transport is blocked. Thus, inhibition of electron
| transport may "lock" CRY in an active state by preventing signaling
| required either to degrade CRY or to convert it to an inactive form. High
| levels of CRY bl ock TIM ubiquitination, suggesting a mechanism by which
| light-driven changes in CRY could control TIM ubiquitination.
AU|Lin
|F.J.
AU|Song
|W.
AU|Meyer-Bernstein
|E.
AU|Sehgal
|A.
YR|2001
TI|Photic signaling by cryptochrome in the Drosophila circadian system.
JR|Bellen, Taylor, 2001
PG|108
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144594	AU 1 Guan et al.	YR 1 2001	TP 1 Abstract	TI 1 Seizure mutants and activity-regulated gene expression in Drosophila.	REFM 1 Bellen, Taylor, 2001: 248		
ID|FBrf0144594
TP|abstract
|Drosophila meeting abstract
MABST|Alterations in neuronal function underlie several forms of synaptic
| plasticity associated with learning and memory, and have important roles in
| pathological states such as epilepsy. We are interested in using Drosophila
| as a model organism to identify and characterize cellular dysfunctions that
| lead to epilepsy, a recurrent seizure disorder that affects over 1% of the
| human populace. To this end, the lab has conducted large-scale behavioral
| screens for temperature-sensitive (TS) paralytic mutations in Drosophila
| that result in an conditional epileptic phenotype and have identified 27
| complementation groups to date that cause conditional recurrent TS
| seizures. Among the mutants are genes defective in mitochondrial proteins,
| the sodium pump, the N-type calcium channel, potassium channel genes, as
| well as novel proteins. To complement our genetic screens we have
| characterized the downstream consequences of increased neuronal activity
| using DNA microarrays to measure gene expression changes induced by seizure
| activity. With the completed Drosophila genome and the large number of
| seizure mutants now available, Drosophila provides an ideal system to
| identify and characterize seizure-regulated genes. Activity-regulated genes
| found in multiple TS seizure mutants include a number of ion channels, cell
| adhesion proteins, signaling molecules and metabolic proteins. As expected,
| several of the TS seizure mutants alter expression of distinct sets of
| genes that are not changed in the other mutants. The most exciting
| candidate genes will be overexpressed or targeted for mutagenesis to assay
| their role in controlling synaptic morphology, synaptic transmission and
| seizure induction/ expression. We will present our current analysis of
| seizure mutants and activity-regulated genes.
AU|Guan
|Z.
AU|Adolfsen
|B.
AU|Wang
|P.
AU|Littleton
|J.T.
YR|2001
TI|Seizure mutants and activity-regulated gene expression in Drosophila.
JR|Bellen, Taylor, 2001
PG|248
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144595	AU 1 Liu et al.	YR 1 2001	TP 1 Abstract	TI 1 Expression of a human DEG/ENAC protein in Drosophila causes necrotic neurodegeneration.	REFM 1 Bellen, Taylor, 2001: 192		
ID|FBrf0144595
TP|abstract
|Drosophila meeting abstract
MABST|Necrotic cell death results from a number of pathological conditions,
| including hypoxia, ischemia, and seizures. Death of neurons by necrosis is
| different from programmed cell death, apoptosis, in that it can be more
| rapid, the cellular organelles swell and the cell membranes break down.
| Because of the importance of this pathway in human diseases and because the
| genes involved in the necrotic cell death pathway are not well known, we
| have began to develop a Drosophila model system to study this process. We
| took advantage of a previously well studied ion channel protein, human BNC1
| (G430C) , which constitutively generates a small cation current when
| heterogously expressed in Xenopus oocytes. We generated several transgenic
| BNC1( G430C) lines under the Gal4/ UAS control system. When these
| transgenic lines were crossed with Elav-Gal4, two lines (C9 and C43) were
| larval lethal; two lines (C3 and C4) survived to adult stage with severe
| defects in movement; and one line (C16) was normal. When these transgenic
| lines were crossed with GMR-Gal4, three lines (C9, C3 and C4) were pupal
| lethal; and one line (C16) had an adult eye defect. Examination of the
| flies using scanning electron microscopy, showed that Elav:: BNC1 (crossed
| with C4) adult eyes were collapsed. Some ommatidia were degenerated and
| there was a circular hole in the center of ommatidium, about 1/ 3 in size
| of the ommatidial diameter. Bacterial infection could also be seen at the
| surface of these eyes. Under transmission electron microscopy, many
| neuronal cells in the head lost their membrane integrity and individual
| cell boundaries became unclear. Some cells contained multiple small black
| bodies. The GMR:: BNC1 line (C16) had eye defects that differed from those
| associated with apoptosis. The eye did not decrease in size and the eye
| surface developed black spots crossing several ommatidia. The distinct
| morphology of these mutants suggest a pathway of death different from
| apoptotic cell death. We are now examining other features in these mutants
| to determine if necrosis was responsible for the cell death.
AU|Liu
|E.
AU|Monniger
|T.O.
AU|Johnson
|W.A.
AU|Welsh
|M.J.
YR|2001
TI|Expression of a human DEG/ENAC protein in Drosophila causes necrotic neurodegeneration.
JR|Bellen, Taylor, 2001
PG|192
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144596	AU 1 Lloyd et al.	YR 1 2001	TP 1 Abstract	TI 1 Multivesicular body formation regulates Notch and EGFR signaling, but not neurotransmitter release.	REFM 1 Bellen, Taylor, 2001: 14		
ID|FBrf0144596
TP|abstract
|Drosophila meeting abstract
MABST|Endo-and exocytosis have been implicated in regulating multiple aspects of
| nervous system development and function. For example, regulation of the
| fusion and recycling of synaptic vesicles is critical for proper synaptic
| transmission. To investigate the role of vesicle trafficking in the nervous
| system, we have analyzed the function of Hrs ( Hepatocyte growth
| factor-regulated tyrosine kinase substrate), an endosome -associated
| protein which has been implicated in multiple vesicle trafficking steps and
| signal transduction pathways. We have identified an EMS-induced truncation
| mutation of Drosophila hrs using heat shock-cDNA and genomic rescue
| constructs. Hrs binds to the t-SNARE SNAP-25 and is highly enriched at
| synaptic boutons of the neuromuscular junction, suggesting that it may
| regulate synaptic vesicle exocytosis. However, electrophysiological
| analysis and FM1-43 uptake studies indicate that Hrs does not regulate exo-
| or endocytosis of synaptic vesicles, in contrast t o previous reports.
| Rather, electron microscopic analysis of mutant synaptic boutons and
| garland cells indicates that Hrs regulates endosome invagination and
| formation of multivesicular bodies (MVBs), intermediates in endosome to
| lysosome trafficking. A role for Hrs in endosomal trafficking is confirmed
| using dye uptake experiments that show that hrs mutant cells have a
| dramatic enlargement of early endosomes and a reduction of low pH
| lysosomes. Next, we analyzed the effects of gain or loss of Hrs funct ion
| on receptor signaling pathways which are believed to be regulated by
| endocytosis. hrs mutant pupae fail to degrade active EGF receptor (Egfr)
| normally, and mutant embryos have enhanced levels of activated MAPK in the
| ventral neuroectoderm. Furthermore, mutant ommatidia have increased numbers
| of photoreceptors, consistent with an increase in Egfr signaling.
| Similarly, hrs mutant embryos fail to degrade the Torso tyrosine kinase
| receptor which leads to enhanced and prolonged MAPK signaling, expanded
| domains of tailless and huckebein terminal gap genes, and severe early
| developmental defects. Interestingly, overexpression of Hrs leads to
| Notch-like phenotypes that are fully suppressed by simultaneous
| overexpression of Notch or Delta, suggesting that Hrs and MVB formation
| regulate Notch signaling as well. These data suggest that Hrs and MVB
| formation function as a negative feedback mechanism to downregulate Notch
| and Egfr signaling during development.
AU|Lloyd
|T.E.
AU|Atkinson
|R.A.
AU|Wu
|M.N.
AU|Zhou
|Y.
AU|Bellen
|H.J.
YR|2001
TI|Multivesicular body formation regulates Notch and EGFR signaling, but not neurotransmitter release.
JR|Bellen, Taylor, 2001
PG|14
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144597	AU 1 Luginbuhl et al.	YR 1 2001	TP 1 Abstract	TI 1 Midline glial cells project glipodia and orchestrate axonal patterning in the CNS.	REFM 1 Bellen, Taylor, 2001: 227		
ID|FBrf0144597
TP|abstract
|Drosophila meeting abstract
MABST|Axonal pathways within the CNS exhibit an orderly bilateral arrangement
| along the midline. Midline glial cells are known to provide molecular cues
| that are crucial for establishing both commissural and longitudinal axonal
| pathways. In order to better understand the nature of cellular
| communications between midline glial cells and various axonal growth cones,
| we examined the cytomorphology of midline glial cells and tested its
| significance during embryonic neurogenesis. First, through use of
| membrane-targeted GFP expression and confocal microscopy, we found that
| midline glial cells bear multiple microprocesses (" gliopodia"), which
| extend and retract dynamically and are capable of directly contacting
| axonal growth cones of both commissural and longitudinal pathways. The peak
| of gliopodia activities is reached during the period corresponding to early
| axogenesis within the embryonic CNS. Second, we demonstrated that gliopodia
| activities are susceptible to regulation of both Rac1 (Drac1) and Cdc42
| (Dcdc42) monomeric GTPases, similar to those of actin-based neuronal
| filopodia. When, by using the GAL4 misexpression system, a dominant
| negative form of either Cdc42 or Rac1 is expressed in midline glial cells,
| the number and length of gliopodia are significantly reduced. In contrast,
| expressing a constitutively active form of either GTPase increases
| gliopodia activities beyond normal levels. Finally, we observed that
| altered gliopodia activities correlate with abnormal pathway organizations
| by a large number of CNS axons. This is reflected by frequent fusions in
| commissural and longitudinal pathways (a robo-like phenotype) or by
| expansion of longitudinal connectives away from the midline and thinning of
| anterior/ posterior commissures (a comm-like phenotype). Our results are
| consistent with the idea that dynamic regulation of gliopodia from midline
| glial cells is essential for proper cellular communication between glial
| cells and neuronal axons during establishment of major axonal pathways
| within the CNS.
AU|Luginbuhl
|D.
AU|Rhine
|J.
AU|Chiba
|A.
YR|2001
TI|Midline glial cells project glipodia and orchestrate axonal patterning in the CNS.
JR|Bellen, Taylor, 2001
PG|227
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144598	AU 1 Billuart et al.	YR 1 2001	TP 1 Abstract	TI 1 Regulating axon branch stability: The role of p190 RhoGAP in repressing a retraction signaling pathway.	REFM 1 Bellen, Taylor, 2001: 89		
ID|FBrf0144598
TP|abstract
|Drosophila meeting abstract
MABST|The molecular mechanisms that regulate axon branch stability are largely
| unknown. Understanding the signaling events that govern this process are
| likely to yield insight into how neuronal plasticity is regulated. Rho
| GTPase activating proteins (RhoGAPs) downregulate signaling from Rho
| GTPases, key regulators of actin cyto-architecture. A genome-wide analysis
| of RhoGAP function in Drosophila using RNA interference identified p190
| RhoGAP as essential for axon branch stability in mushroom body neurons in
| the maturing and adult brain. p190 RhoGAP inactivation leads to axon branch
| retraction, a phenotype mimicked by activation of GTPase RhoA and its
| downstream effector kinase Drok, and modulated by the level and
| phosphorylation state of myosin regulatory light chain. We propose the
| existence of a "retraction signaling pathway" from RhoA to the regulation
| of non-muscle myosin II and the actin cytoskeleton. As we recently
| described, this pathway is also involved in controlling actin architecture
| during the development of planar cell polarity (Winter et al., Cell, 2001).
| Our data indicates that this pathway is actively repressed by p190 RhoGAP
| to maintain axon stability. Local regulation of this repressor could
| control axon branch stability and structural plasticity of neurons. Indeed,
| p190 RhoGAP appears to be negatively regulated by integrin and Src, both
| implicated in neural plasticity.
AU|Billuart
|P.
AU|Winter
|C.G.
AU|Zhao
|X.
AU|Maresh
|A.
AU|Luo
|L.
YR|2001
TI|Regulating axon branch stability: The role of p190 RhoGAP in repressing a retraction signaling pathway.
JR|Bellen, Taylor, 2001
PG|89
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144599	AU 1 Macleod et al.	YR 1 2001	TP 1 Abstract	TI 1 New calcium imaging techniques for Drosophila neuromuscular junctions test the need for synaptic vesicles in calcium channel function.	REFM 1 Bellen, Taylor, 2001: 35		
ID|FBrf0144599
TP|abstract
|Drosophila meeting abstract
MABST|Calcium ions are essential for neurotransmitter release. While information
| on presynaptic intracellular calcium dynamics is critical to test
| hypotheses relating to synaptic function, such data have been difficult to
| collect in the Drosophila neuromuscular junction (NMJ). We developed an
| improved imaging technique with the following advantages: (a) avoids
| excessive background fluorescence in muscle fibers caused by permeant AM
| forms of calcium indicators; (b) increases the lifetime of preparations.
| Dextran-conjugated calcium indicators were loaded into presynaptic
| terminals of larval NMJs by forward-filling cut ends of motor axons,
| enabling measurements of intracellular calcium dynamics. An improved
| hemolymph-like solution contributed to the preparation's vitality. The
| robust indicator signal and reduced background provided improved conditions
| for measurement of intracellular calcium concentration dynamics. Calcium
| signals produced by single nerve impulses were readily detected. We could
| also collect data on calcium levels in the NMJs concurrently with
| electrophysiological data. To test the hypothesis that synaptic vesicles
| are required for proper functioning of calcium channels, we examined NMJs
| of the temperature sensitive shi bire (shi ts1 ) mutant in which synaptic
| vesicles are largely depleted by motor axon stimulation above 29� C.
| Presynaptic calcium signals persisted at temperatures that are
| non-permissive for synaptic transmission. Supported by CIHR grants to H. L.
| A. and M. P. C.
AU|Macleod
|G.T.
AU|Karunanithi
|S.
AU|Dawson-Scully
|K.D.
AU|Charlton
|M.P.
AU|Atwood
|H.L.
YR|2001
TI|New calcium imaging techniques for Drosophila neuromuscular junctions test the need for synaptic vesicles in calcium channel function.
JR|Bellen, Taylor, 2001
PG|35
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144600	AU 1 Magalhaes et al.	YR 1 2001	TP 1 Abstract	TI 1 A functional genomics approach to axon guidance: Microarray analysis of mutations that affect midline crossing in Drosophila.	REFM 1 Bellen, Taylor, 2001: 70		
ID|FBrf0144600
TP|abstract
|Drosophila meeting abstract
MABST|We are interested in genetic interactions occurring during axon guidance in
| the Drosophila embryo. Many different mutants that affect axon guidance in
| the embryonic central nervous system have been isolated and their genetic
| interactions studied. For example, Roundabout (Robo), Slit and
| Commissureless (Comm) are important molecules that control whether or not
| axons cross the CNS midline. Robo is a transmembrane protein expressed in
| axons and is a receptor for the midline repellent Slit. In robo loss of
| function (LOF) mutants many axons inappropriately cross and recross the
| midline. In robo gain of function (GOF) mutants too few axons cross the
| midline. Comm is a surface protein expressed at the midline that negatively
| regulates Robo. In comm LOF mutants no axons cross the midline. In comm GOF
| mutants axons cross and recross the midline in a manner similar to robo
| mutants. Slit is a large extracellular matrix protein, expressed by midline
| glia and is the ligand for the Robo receptor. In slit LOF mutants neurons
| grow toward the midline and fail to exit. It is not clear whether the
| function of these molecules in axon guidance requires changes in gene
| expression. To determine whether differential gene expression is
| responsible for aberrant axon behaviour in these mutants, we have analyzed
| five mutants using microarrays: robo LOF, robo GOF, comm LOF, comm GOF, and
| slit LOF. Analyzing both loss of function (LOF) and gain of function (GOF)
| mutants allows microarray analysis to be grounded on the wealth of
| available genetic information. Microarrays are well suited to Drosophila
| embryonic nervous system as it occupies a large portion of the whole
| organism and large amounts of tissue can be collected. By analyzing genes
| that change in these mutant conditions we hope to uncover additional genes
| involved in the slit /robo guidance pathway. We will present the results of
| statistical analysis of the microarray data.
AU|Magalhaes
|T.R.
AU|Li
|L.S.
AU|Goodman
|C.S.
YR|2001
TI|A functional genomics approach to axon guidance: Microarray analysis of mutations that affect midline crossing in Drosophila.
JR|Bellen, Taylor, 2001
PG|70
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144601	AU 1 Magarinos et al.	YR 1 2001	TP 1 Abstract	TI 1 Apterous, a LIM-homeodomain transcription factor: Its role in neuropeptides regulation.	REFM 1 Bellen, Taylor, 2001: 36		
ID|FBrf0144601
TP|abstract
|Drosophila meeting abstract
MABST|Apterous null mutants present a pleiotropic phenotype affecting
| developmental processes such as dorsal wing specification, distal proximal
| leg determination, and axonal guidance. They also present physiological
| defects such as female sterility due to reduced juvenile hormone levels,
| and behavioral defects such as abnormal sexual performance. Transcriptional
| regulation of the FMRF-a neuropeptide in the ventral ganglion
| neurosecretory Tv-cells by Apterous has also been reported, (Benveniste et
| al 1998). This therefore, defines apterous implications in neuronal
| identity. We now describe a role for Apterous in regulating the expression
| of Leucokinin IV in a subset of neurons in the brain, and of the Small
| Cardioactive Peptide B (SCP B ) in the above mentioned Tv-cells. Our
| results that show rescue of FMRF-amide through Apterous expression in cells
| others than the Tv-cells, suggest an alternative way of FMRF-amide
| regulation by Apterous in these cells. Therefore, the importance of
| Apterous in the production of neuropeptides is underlined and its mode of
| action is discussed.
AU|Magarinos
|M.
AU|Herrero
|P.
AU|Martinez
|P.
AU|Canal
|I.
YR|2001
TI|Apterous, a LIM-homeodomain transcription factor: Its role in neuropeptides regulation.
JR|Bellen, Taylor, 2001
PG|36
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144602	AU 1 Malpel et al.	YR 1 2001	TP 1 Abstract	TI 1 Larval visual organ and adult extraretinal photoreceptors sequentially connect to clock neurons during Drosophila brain development.	REFM 1 Bellen, Taylor, 2001: 136		
ID|FBrf0144602
TP|abstract
|Drosophila meeting abstract
MABST|The larval optic nerve, or Bolwig nerve (BN), is one possible input pathway
| for light into the circadian clock of the Drosophila larval brain. We first
| showed that the BN already contacts clock cells (the lateral neurons) in
| the embryonic brain. Analysis of visual system-defective genotypes showed
| that the specific absence of the afferent BN results in a severe reduction
| of the lateral neurons' dendritic arborization, whereas a functional
| perturbation of the nerve induces alterations of the dendritic morphology.
| In the wild -type, the disappearance of the BN in the early pupa was also
| accompanied by remodeling of the arborization of the lateral neurons.
| Approximately 1.5 days later, a nerve terminal that comes from the
| Hofbauer-Buchner eyelet, a putative photoreceptive organ for the adult
| circadian clock, contacts the lateral neurons. Despite the developmental
| discontinuity and morphological differences between these larval and adult
| visual inputs, both types of extra-retinal photoreceptors expressed
| rhodopsins RH5 and RH6, as well as the norpA-encoded phospholipase C. The
| eyelet would therefore not account for the previously described
| norpA-independent circadian photoreception of adult Drosophila, suggesting
| the existence of yet uncharacterized photoreceptors.
AU|Malpel
|S.
AU|Klarsfeld
|A.
AU|Rouyer
|F.
YR|2001
TI|Larval visual organ and adult extraretinal photoreceptors sequentially connect to clock neurons during Drosophila brain development.
JR|Bellen, Taylor, 2001
PG|136
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144603	AU 1 Manev et al.	YR 1 2001	TP 1 Abstract	TI 1 RNA interference in adult Drosophila.	REFM 1 Bellen, Taylor, 2001: 71		
ID|FBrf0144603
TP|abstract
|Drosophila meeting abstract
MABST|RNA interference (RNAi) is a mechanism of gene silencing that can be
| triggered by introducing a specific double-stranded RNA (dsRNA) into cells
| expressing the appropriate molecular machinery, which then degrades the
| corresponding endogenous mRNA. RNAi can be used for investigating gene
| function and creating functional "knockout" organisms. Here we show that
| RNAi can be induced in adult fruit flies by injecting dsRNA into the
| abdomen of anesthetized Drosophila, and that this method can also target
| genes expressed in the CNS. We targeted the lacZ gene that encodes a
| protein with b -galactosidase activity and we used transgenic flies
| expressing lacZ either in the midgut or in the CNS. Injection of lacZ dsRNA
| abolished enteric b -galactosidase activity in a time -dependent manner;
| more than 24 h was needed for the RNAi process to reduce/ abolish the
| transgenic lacZ mRNA content and b -galactosidase activity. Injection of
| structurally unrelated dsRNA for the green fluorescent protein gene did not
| reduce b -galactosidase activity. The inhibitory effect of lacZ dsRNA was
| not restricted to the enteric expression of the gene. Thus, although
| injected into the abdomen, lacZ dsRNA was effective in inhibiting b
| -galactosidase activity in the CNS of transgenic enhancer-trap lines
| expressing lacZ in the optic lobe or the antennal lobe; both b
| -galactosidase activities were inhibited 72 h after dsRNA injection. The
| simplicity of this technique may provide researchers with an accessible
| tool for studying gene function in the CNS of adult fruit flies. The
| advantage of this method compared with the use of mutant flies is that a
| normal adult organism can be studied, i. e., the targeted gene can be
| functionally silenced without interfering with the organism's development.
AU|Manev
|H.
AU|Dzitoyeva
|S.
AU|Dimitrijevic
|N.
YR|2001
TI|RNA interference in adult Drosophila.
JR|Bellen, Taylor, 2001
PG|71
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144604	AU 1 Marques et al.	YR 1 2001	TP 1 Abstract	TI 1 Signaling through the Drosophila type II BMP receptor wishfull thinking is required for proper synaptic maturation and function.	REFM 1 Bellen, Taylor, 2001: 250		
ID|FBrf0144604
TP|abstract
|Drosophila meeting abstract
MABST|The formation and maintenance of synapses require closely coordinated
| pre-and post-synaptic interactions, generally thought to involve
| intercellular signaling mechanisms. However, the molecular identity of
| these pathways remains largely unknown. Here we report a novel signaling
| pathway involving the type II receptor for BMPs wishful thinking (wit). wit
| is expressed in the embryonic and larval nervous system, as well as in the
| gut and imaginal disks. wit mutants die as pharate adults, with weak and
| partially penetrant patterning defects and no obvious morphological
| abnormalities. Closer examination reveals that embryonic motoneurons and
| neurosecretory cells of the larval nervous system are affected, as
| indicated by the loss of expression of specific markers. Morphological
| characterization of the third instar larval neuromuscular junction
| indicates a substantial reduction in synapse size. Electrophysiological
| studies show that evoked synaptic transmission is severely compromised,
| with normal quantal size and a five-fold decrease in the frequency of
| spontaneous release. The lethality and associated phenotypes can be rescued
| with neuronal expression of the wit cDNA. These results indicate that Wit
| acts as a neuronal receptor essential for the development and maturation of
| normal synaptic function. Immunohistochemical localization of components of
| the BMP signaling system to the neuromuscular junction synapse strongly
| suggests that growth factors of this family are involved in retrograde
| signaling during synapse formation or maturation.
AU|Marques
|G.
AU|Shimell
|M.J.
AU|Duchek
|P.
AU|Haerry
|T.
AU|Bao
|H.
AU|Zhang
|B.
AU|O'Connor
|M.B.
YR|2001
TI|Signaling through the Drosophila type II BMP receptor wishfull thinking is required for proper synaptic maturation and function.
JR|Bellen, Taylor, 2001
PG|250
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144605	AU 1 Martin	YR 1 2001	TP 1 Abstract	TI 1 Some parameters of the sexually dimorphic locomotor behavior controlled by the juvenile hormone in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 178		
ID|FBrf0144605
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila, in the continuity of the morphologic, genetic and molecular
| characterisation of the neurones responsible for the sexual dimorphism in
| locomotor activity, recently, we have developed a new technique of
| video-tracking to refine, more precisely, the locomotor activity parameters
| which differ between males and females. Mainly, two parameters differ: the
| number of start/ stop ( for a given time period), and the spatial
| orientation. In a step further, using the five enhancer-trap P[ Gal4]
| feminising lines that have been previously identified (Gatti et al.,
| Current Biology, Vol 10, 2000) to drive the UAS-tranformer gene in the few
| neurones located in the pars-intercerebralis (PI), lead in males, to the
| feminisation of the number of start/ stop. However, inversely, the spatial
| orientation is not feminised in those five lines, suggesting that this
| component of locomotor activity is not under the control of those neurones.
| Additionally, it has been suggested that the neurones of the PI could
| control the secretion of the corpus cardiacum-corpus allatum (cc-ca), and
| more specifically, the Juvenile Hormone (JH). To test this hypothesis, we
| used a pharmacological approach. In Drosophila males, the injection of an
| inhibitor of the JH biosynthesis by the corpora allata, mimics the effect
| of the feminisation of the number of start/ stop. This strongly suggests
| that the feminisation process could be conveyed by the JH, and
| consequently, supports the implication of the neurones of the pars
| intercerebralis in the control of the cc-ca secretion and the feminisation process.
AU|Martin
|J.R.
YR|2001
TI|Some parameters of the sexually dimorphic locomotor behavior controlled by the juvenile hormone in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|178
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144606	AU 1 Mathew et al.	YR 1 2001	TP 1 Abstract	TI 1 GUK-holder, a novel synaptic protein that links Discs-Large and Scribble at the neuromuscular junction.	REFM 1 Bellen, Taylor, 2001: 90		
ID|FBrf0144606
TP|abstract
|Drosophila meeting abstract
MABST|Synaptic transmission between a neuron and its target is crucially dependent
| upon the precise spatial arrangement of proteins in the pre-and
| postsynaptic apparatus. Recent studies have implicated PDZ
| domain-containing proteins, such as the tumor suppressor protein Discs
| Large (DLG) (MAGUK -Membrane Associated Guanylate Kinase family of
| proteins), as having a central role in the processes of synapse assembly
| and plasticity. These proteins mediate the organi zation of synaptic
| components into elaborate and precise protein complexes. Previous studies
| have shown that the PDZ domains of DLG, mediate clustering of Shaker K +
| channels and of the cell adhesion molecule Fasciclin II at the
| glutamatergic synapses of the Drosophila neuromuscular junction. The
| mammalian DLG homolog PSD-95 similarly clusters Shaker-type K + channels
| and NMDA receptor subunits at the vertebrate central synapse via its PDZ
| domains. However, it is not yet known how different complexes are linked
| together. It has been proposed that in the absence of guanylate kinase
| activity the GUK domain of MAGUKS, has evolved to serve another function,
| that of a protein-protein interaction domain. By performing a yeast-two
| hybrid screen using the GUK domain as 'bait', we have identified a novel
| cytosolic protein GUK-holder (GUKh) which interacts with the GUK domain of
| the PDZ protein Discs-Large (DLG). Interestingly, GUKh also interacts with
| a second tumor suppressor PDZ protein, Scribble (SCRIB), that colocalizes
| with DLG at the synaptic and epithelial junctions. GUKh thus forms a link
| between these two scaffolding proteins, establishing a PDZ network. Here we
| show that GUK-holder, like DLG, is required for proper synapse maturation
| and for proper localization of SCRIB. These studies suggest a mechanism by
| which PDZ-protein function may be coordinated during synapse assembly and modification.
AU|Mathew
|D.
AU|Gramates
|L.S.
AU|Packard
|M.
AU|Gorcyzca
|M.
AU|Bilder
|D.
AU|Budnik
|V.
YR|2001
TI|GUK-holder, a novel synaptic protein that links Discs-Large and Scribble at the neuromuscular junction.
JR|Bellen, Taylor, 2001
PG|90
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144607	AU 1 McCabe et al.	YR 1 2001	TP 1 Abstract	TI 1 A BMP signaling pathway regulates synpatic plasticity at the Drosophila neuromuscular junction.	REFM 1 Bellen, Taylor, 2001: 93		
ID|FBrf0144607
TP|abstract
|Drosophila meeting abstract
MABST|Synaptic structure and function is tightly regulated to ensure efficacy of
| communication. During development, Drosophila larva undergo a rapid
| expansion in muscle volume accompanied by a concomitant increase in both
| the size and complexity of neuromuscular synapses. We have conducted a
| genetic screen for molecules that are required for this structural
| plasticity. We have identified several genes in a Bone Morphogenetic
| Protein (BMP) signaling pathway as being essential for structural growth of
| the larval neuromuscular junction. We isolated mutations that disrupt
| signaling a several points in the BMP pathway. These include mutants in a
| novel type II BMP receptor, wishful thinking (wit) in addition to mutants
| in previously identified type I BMP receptors and downstream effectors
| including Smad intracellular mediator molecules. Loss of function mutations
| in these BMP signaling pathway components results in a dramatic reduction
| of neuromuscular junction size as well as electrophysiological and
| ultrastructural defects. Targeted transgenic disruption and rescue
| experiments combined with immunohistochemical analysis show that the BMP
| signaling pathway is required in motoneurons and is cell autonomous.
| Initial muscle innervation is unaffected in these mutants indicating that
| this pathway specifically regulates synaptic plasticity. The identification
| of a signaling pathway that regulates plasticity at the Drosophila
| neuromuscular junction offers the opportunity to dissect the relationship
| between synaptic structure and function. Supported by: Wellcome Trust Prize
| Traveling Fellowship (B. McC), Howard Hughes Medical Institute (C. S. G)
AU|McCabe
|B.D.
AU|Aberle
|H.
AU|Haghighi
|A.P.
AU|Parnas
|D.
AU|Fetter
|R.
AU|Goodman
|C.S.
YR|2001
TI|A BMP signaling pathway regulates synpatic plasticity at the Drosophila neuromuscular junction.
JR|Bellen, Taylor, 2001
PG|93
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144608	AU 1 McDonald and Rosbash	YR 1 2001	TP 1 Abstract	TI 1 Screening for clock controlled genes using differential display and microarray technology.	REFM 1 Bellen, Taylor, 2001: 72		
ID|FBrf0144608
TP|abstract
|Drosophila meeting abstract
MABST|Most eukaryotic organisms govern multiple aspects of their metabolism and
| behavior with a circadian (ca. 24 hour) pacemaker. In all species that have
| been investigated in detail, this pacemaker includes a negative feedback
| loop operating at the transcriptional level. Genetics in both flies and
| mice led to the discovery of a conserved transcription factor, which is
| critical for this feedback loop and therefore for circadian function. This
| factor consists of the heterodimer, CLOCK and CYCLE (CLOCK and BMAL1 in
| mammals), which binds to conserved E boxes and activates the transcription
| of circadian genes. These include genes that are part of the Drosophila
| central pacemaker, period and timeless, as well as downstream genes that
| affect circadian outputs but are not part of the clock itself, e. g.,
| vrille, takeout, and pdf. We hypothesized that CLOCK/ CYCLE is at the top
| of a hierarchy that includes many additional clock and clock-controlled
| genes. We are interested in direct CLOCK/ CYCLE targets as well as defining
| the collection of clock-controlled genes. To screen for the latter set in a
| comprehensive manner, we have been using microarrays as well as
| differential display to compare the transcriptional profiles of wild type
| Canton S head mRNA with mRNA from clock-mutant flies. Approximately 2.5% of
| head mRNAs undergo circadian cycling and at least another 2.5% do not cycle
| but are affected quantitatively in mutant vs wild-type flies. The high
| fraction of the genome (&gt; 600 transcripts if one accepts a 13,000 gene
| number) under clock-control explains the profound behavioral phenotypes of
| this mutant strain.
AU|McDonald
|M.J.
AU|Rosbash
|M.
YR|2001
TI|Screening for clock controlled genes using differential display and microarray technology.
JR|Bellen, Taylor, 2001
PG|72
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144609	AU 1 McGuire et al.	YR 1 2001	TP 1 Abstract	TI 1 The role of Drosophila mushroom body signaling in olfactory memory.	REFM 1 Bellen, Taylor, 2001: 109		
ID|FBrf0144609
TP|abstract
|Drosophila meeting abstract
MABST|A large body of evidence implicates the mushroom bodies (MBs) of Drosophila
| as important neuroanatomical centers for learning and memory of olfactory
| information. However, to date very little has been described regarding the
| temporal dynamics of MB signaling required during the different phases of
| memory processing. We have begun to address this issue by utilizing a new
| molecular tool based on a temperature sensitive (ts) allele of the shibire
| gene product, which encodes a dynamin GTPase involved in synaptic vesicle
| recycling. At 25 o C, synaptic transmission in cells expressing the ts
| shibire gene is normal, whereas at 32 o C, synaptic transmission is
| blocked. Using the Gal4/ UAS system to express the ts shibire gene
| specifically in MB neurons, we have perfor med temperature shift
| experiments to address the role of these cells in memory acquisition,
| consolidation, and retrieval. Our data indicate that, surprisingly,
| signaling through the MB a / b neurons is required during memory retrieval,
| but not during memory acquisition or consolidation. These results suggest
| that acquisition and consolidation of olfactory memories occur upstream of
| the MB synapse upon follower neurons, either in MB neurons themselves or in
| upstream circuits. Retrieval of these memories up to 3 hours after training
| then engages signaling through a subset of the MB neurons, involving the a
| / b lobes.
AU|McGuire
|S.E.
AU|Le
|P.T.
AU|Davis
|R.L.
YR|2001
TI|The role of Drosophila mushroom body signaling in olfactory memory.
JR|Bellen, Taylor, 2001
PG|109
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144610	AU 1 McKinnon et al.	YR 1 2001	TP 1 Abstract	TI 1 A misexpression screen reveals modulators of axon pathfinding in the Drosophila midline.	REFM 1 Bellen, Taylor, 2001: 228		
ID|FBrf0144610
TP|abstract
|Drosophila meeting abstract
MABST|We have carried out a modular GAL4/ UAS misexpression screen to identify
| molecules which, when expressed by a small subset of neurons whose axons
| cross the CNS, alter axon pathfinding. Our strategy employed the
| bidirectional 'Gene Search' P-element (Toba et al., Genetics 151, 725-737,
| 1999) and a UAS-tau-GFP transgene to visualize neurons in living embryos.
| Eagle-GAL4 was used to drive expression in two small groups of neurons, one
| projecting in the anterior commissure (AC), the other in the posterior
| commissure (PC). We screened 858 independent GS insertions on the 2nd and
| 3rd chromosomes, and defects were observed in 28 lines (3.3%). Ten of the
| 28 lines had apparent defects in cell fate and/ or cell body position and
| were not examined further, while 18 had specific axon pathfinding defects.
| The insertion sites for 14 of these lines has been determined by DNA
| sequence analysis using an inverse PCR approach. Eleven insertions mapped
| to previously characterized genes, and 3 mapped to uncharacterized loci.
| Molecules encoded by these genes included two known axon guidance receptors
| (Robo 2 and Unc 5), as well as a relative of the Derailed guidance receptor
| (Drl-2). Other cell surface molecules identified included Capricious, Gasp
| precursor, and an uncharacterized protein (CG6550). Nuclear regulatory
| proteins identified included tramtrack, Lilliputian, REST, Spen, phtf, and
| Kruppel homolog 2. These studies thus identify both known and novel
| molecules whose expression modulates the ability of interneurons to make
| appropriate choices in axon pathfinding while crossing the Drosophila CNS
| midline. Supported by grants from the NIH to R. McK. and J. B. T.
AU|McKinnon
|R.D.
AU|Yoshikawa
|S.
AU|O'Keefe
|D.D.
AU|Thomas
|J.B.
YR|2001
TI|A misexpression screen reveals modulators of axon pathfinding in the Drosophila midline.
JR|Bellen, Taylor, 2001
PG|228
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144611	AU 1 McNabb and Truman	YR 1 2001	TP 1 Abstract	TI 1 Light stimulates a rapid eclosion response that requires eclosion hormone and both sets of retinal photoreceptors.	REFM 1 Bellen, Taylor, 2001: 110		
ID|FBrf0144611
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila, eclosion (adult ecdysis or emergence) is a circadian behavior
| that is masked by early morning light under photoperiod conditions.
| Previously, the eclosion lights-on (LOn) response was shown to result in an
| emergence peak within an hour of exposure to light. We have shown that the
| LOn response is robust, rapid, and independent of developmental rate. It
| requires functional EH neurons. The eyes, the ocelli, and chaoptin are
| required for the response, but photoreceptors R1-6 are not. Wing spreading,
| a post-eclosion behavior that is also regulated by EH, is not influenced by
| LOn. To test the LOn response, all flies were entrained to a 14L: 8 D cycle
| then subjected to ~750 lux of fluorescent light either at the normal time
| of LOn, after normal LOn, or prior to normal LOn. Flies were collected
| every 10 min around the time of LOn, and at the end of each day. For the
| basic description of the response we used w 1118 /y w UAS-rpr flies that
| had undergone preliminary analysis previously. We demonstrated that the LOn
| response was robust and independent of development by collecting all adults
| that emerged from a single day's embryo collection. A LOn response that
| resulted in a 4-to 16-fold increase in eclosion within 10 min was detected
| on each of the 4 days during which eclosion ensued. We showed that the
| rapid eclosion burst was due to light itself and not simply a response to
| the entraining signal. Administering a light pulse to flies 1 hr after
| normal LOn produced a strong LOn response. The response ended immediately
| when the flies were returned to the dark. We also showed that flies acquire
| LOn responsiveness about an hour prior to and retain it for at least 2 hrs
| after normal LOn. Since EH is normally released 40-60 minutes prior to
| eclosion, the timing of the onset of responsiveness suggests that LOn
| competence may be due to EH release. We investigated the role of EH in the
| LOn response by testing both EH cell knockout flies (EHups-Gal4; y w
| UAS-rpr) and flies that expressed TxTLC (EHups-Gal4; UAS-TNT-L) in their EH
| neurons. Since neither strain had a LOn response, EH function must be
| required. Immunocytochemical experiments show that TxTLC expression in the
| EH cells inhibits EH release, suggesting that EH release per se is
| necessary. Immunocytochemistry also showed that light directly stimulates
| EH release. In addition to the EH neurons, optic photoreceptors in both the
| ocelli and the compound eyes also appear to be required for the LOn
| response. Flies that lacked either ocelli, ocelliless (oc 1 ), and flies
| that lack eyes (eyes absent; cli eya-2 ) mutants lacked the response. Flies
| that are mutant for chaoptin (chp 7 ) or rhodopsin 1 (nina E5 ) also lacked
| the LOn response. Wing spreading took longer among strains that displayed
| the LOn response than in those that lacked it, apparently due to the
| specific acceleration of eclosion in strains that exhibited a LOn response.
| Experiments by others in the moth Manduca sexta show that EH release
| activates a central network of neurons that express crustacean cardioactive
| peptide (CCAP) and cause ecdysis behavior. Ecdysis is subsequently delayed
| due to a descending inhibition. In both Manduca and Drosophila,
| decapitation results in rapid eclosion, consistent with the removal of that
| inhibition. We believe the LOn response similarly results from the
| immediate release of the descending inhibition of ecdysis. In contrast,
| wing expansion behavior is not advanced by the LOn signal, suggesting a
| divergence in behavioral regulatory effects of EH function.
AU|McNabb
|S.L.
AU|Truman
|J.W.
YR|2001
TI|Light stimulates a rapid eclosion response that requires eclosion hormone and both sets of retinal photoreceptors.
JR|Bellen, Taylor, 2001
PG|110
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144612	AU 1 Edwards et al.	YR 1 2001	TP 1 Abstract	TI 1 Eyelet in Drosophila: Its development and putative circadian function.	REFM 1 Bellen, Taylor, 2001: 194		
ID|FBrf0144612
TP|abstract
|Drosophila meeting abstract
MABST|At the compound eye's posterior rim, paired Hofbauer-Buchner eyelets, each
| containing 4 photoreceptors, project axons to the anterior medulla along
| the same path as the nerve from Bolwig's organ, paired clusters of 12
| larval photoreceptors. Neither function nor developmental origin for eyelet
| is known. Bolwig's organ loses 24B10 immunoreactivity, and is suggested to
| degenerate in the early pupa, but b -gal expression in reporter line BS23
| (Kr-BO-lacZ) driven by a promoter for Kr�ppel reveals that it persists
| through pupal life to transform into eyelet. Bolwig's organ also expresses
| immunoreactivity to Rh6, which is retained or later re-expressed in eyelet.
| Bolwig's organ retracts from the larval mouthhooks, coming to lie beneath
| the retinal basement membrane, after the eye imaginal disc everts. By P+ 5%
| the retracting cells form two clusters; by P+ 20% only 3-6 cells, usually
| 4, express b -gal, others dying. During its transformation, Bolwig's nerve
| terminals associate closely with the Lateral Neurons (LNs), which are
| required for circadian rhythmicity. The larval circadian pacemaker center
| comprises 5 small ventral LNs (s-LNv), 4 immunoreactive to neuropeptide
| PDH. Bolwig's nerve terminals overlap these cells' PDH-ir arborizations.
| Bolwig's organ could thus provide input to circadian larval entrainment. In
| the pupa, faint 24B10 immunolabeling reappears in Bolwig's nerve by P+ 50%.
| Rhabdomeric structures compatible with photoreceptor function first appear
| at P+ 60% Concurrently, somata of large LNv and their neurites first show
| PDH-ir. Spatial overlap with l-LNv neurites suggests that eyelet transfers
| photic information to circadian pacemaker cells, just as the antecedent
| Bolwig's organ did in the larva. To test this possibility, we compared the
| spectral sensitivity of entrainment between sine oculis (so 1 ), which has
| a normal Bolwig's organ and retains eyelet, and glass 60j (gl 60j ) which
| lacks eyelet. We first generated so 1 ;gl 60j flies with identical
| screening pigment in their eyes to so flies, and then measured action
| spectra for entraining activity rhythms in adult so 1 and so 1 ;gl 60j
| flies. so flies have two peaks, at 420 nm and ~ 480 nm, whereas so 1 ;gl
| 60j flies lack the 480 nm peak, suggesting that it stems from eyelet. To
| examine entrainment of the fly's activity rhythm we subjected flies to a 6
| h phase advance of the light/ dark-cycle. Flies resynchronize to a 6 h
| phase advance either by following the shift and advancing their phase by 6
| h, or by delaying the phase by 18 h. Most so 1 ;gl 60j flies phase-advanced
| their clock, whereas many so 1 flies phase-delayed their clock. We
| therefore propose that, in the absence of the compound eyes, eyelet
| mediates mainly phase delays.
AU|Edwards
|T.N.
AU|Helfrich-Forster
|C.
AU|Yasuyama
|K.
AU|Wisotzky
|B.
AU|Schneuwly
|S.
AU|Hofbauer
|A.
AU|Meinertzhagen
|I.A.
YR|2001
TI|Eyelet in Drosophila: Its development and putative circadian function.
JR|Bellen, Taylor, 2001
PG|194
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144613	AU 1 Meinertzhagen and Borycz	YR 1 2001	TP 1 Abstract	TI 1 ebony and tan: Possible roles in histamine metabolism at photoreceptor terminals in the optic lobe.	REFM 1 Bellen, Taylor, 2001: 193		
ID|FBrf0144613
TP|abstract
|Drosophila meeting abstract
MABST|Histamine (HA), a transmitter at the compound eye's photoreceptor terminals,
| is synthesized under the control of histidine decarboxylase (hdc).
| Blindness and lack of histamine, phenotypes of the hdc null JK910, are
| rescued in flies given exogenous histamine by uptake into photoreceptors.
| Histamine release is tonic, from terminals of R1-R6 in the lamina and R7,
| R8 in the medulla. After release, histamine could be recovered by: 1) such
| direct reuptake at terminals; 2) new synthesis via hdc; or 3) metabolic
| pathways; evidence exists for the first two of these. Terminals of R1-R6
| innervate monopolar cells (LMCs). Light-evoked histamine release causes
| responses in LMCs recorded in the electroretinogram (ERG) as on-and
| off-transients. tan and ebony, mutants with reciprocally defective
| transients, regulate b -alanine conjugation of dopamine (DA): ebony encodes
| b -alanyl- DA-synthase; tan encodes the reciprocal hydrolase for b
| -alanyl-DA � DA + b -alanine. Their ERG defects are paradoxical because the
| lamina lacks DA-ergic neurons and neither tan nor ebony has been implicated
| in metabolizing the lamina's chief amine, histamine. Yet Ebony peptide
| expresses in glia at sites in the lamina and distal medulla coinciding with
| sites of histamine release (see Hovemann abstract). Can tan and ebony
| possibly regulate a Drosophila pathway for histamine metabolism via its b
| -alanyl derivative, carcinine (CA)? We investigated this using HPLC with
| electrochemical detection. The histamine content of the Drosophila head was
| as follows: ~2 ng for C-S wt, of which sine oculis had 70% less; ~200 pg
| for tan ; ~700 pg for an ebony excision allele and ~900 pg for ebony 1 .
| Immunoreactivity to histamine also changed. For histamine metabolites, the
| HPLC peak for carcinine in C-S flies overlapped other peaks. First,
| therefore, we used Sarcophaga, injecting its much larger head with 3 H-HA
| to test whether the carcinine peak was fed by 3 H-HA. Fractions of
| Sarcophaga heads prepared for HPLC, collected 1 min to 6 h after the
| injection and counted for 3 H in a scintillation counter, had a clear 3 H
| peak at the retention time for carcinine. Thu s, carcinine is a candidate
| metabolite of histamine, its 3 H peak appearing rapidly, but most clearly 5
| -30 min after injection. Similarly, dehydrated Drosophila drink from a
| droplet of 3 H-HA in 4% glucose, thereby taking up histamine. Although a
| carcinine 3 H peak was not seen 40 min later in either C-S or ebony, it was
| clear in tan and, less clearly, in hdc JK910 . Apparently: a) tan cannot
| hydrolyze 3 H-CA to liberate 3 H-HA; b) wt hydrolysis is complete, leaving
| little carcinine; c) ebony lacks both a synthetic pathway for carcinine and
| a 3 H-CA peak. In parallel with b -alanyl conjugation, other 3 H
| metabolites progressively accumulate. These may be MAO metabolites, because
| a MAO inhibitor, Pargyline, increases both 3 H-HA and 3 H-CA. Support: MRC
| MOP-36453 (to I. A. M.); NATO fellowship (to J. B.).
AU|Meinertzhagen
|I.A.
AU|Borycz
|J.
YR|2001
TI|ebony and tan: Possible roles in histamine metabolism at photoreceptor terminals in the optic lobe.
JR|Bellen, Taylor, 2001
PG|193
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144614	AU 1 Meyer-Bernstein et al.	YR 1 2001	TP 1 Abstract	TI 1 Regulation of the Drosophila photosensitivity rhythm by timeless protein.	REFM 1 Bellen, Taylor, 2001: 111		
ID|FBrf0144614
TP|abstract
|Drosophila meeting abstract
MABST|A circadian rhythm in visual sensitivity has been documented in several
| species including Drosophila melanogaster. This rhythm is likely to be an
| output of the retinal clock although the mechanism by which the clock
| confers this rhythmicity is unknown. By conducting a yeast two-hybrid
| screen for protein partners of the known clock component, TIMELESS (TIM),
| we found that it interacts with the NorpA protein. The norpA gene encodes a
| phosphoinositol specific phospholipase C and is a crucial component of the
| Drosophila visual transduction pathway. Subsequent co-immunoprecipitation
| from fly head extracts confirmed the interaction. Using double label
| fluorescent immunohistochemistry, we determined that the most likely site
| of interaction between these two proteins is the retinal photoreceptor
| cells. Based on these data, we hypothesized that the TIM/ NorpA interaction
| underlies the circadian rhythm in visual sensitivity. We measured the
| levels of retinal visual pigments in vivo and confirmed previous reports of
| a circadian cycle in visual sensitivity with a peak during the nighttime
| hours. We also demonstrated that in flies with constitutive levels of TIM,
| the circadian cycling of visual sensitivity was abolished. Together with a
| previous report indicating that the circadian cycling of visual pigments is
| lost in norpA mutants, these data support our hypothesis that the rhythm of
| visual sensitivity is controlled through a direct effect of TIM on NorpA.
| These data do not preclude a role for NorpA in the modulation of TIM function.
AU|Meyer-Bernstein
|E.L.
AU|Lin
|F.J.
AU|Sehgal
|A.
YR|2001
TI|Regulation of the Drosophila photosensitivity rhythm by timeless protein.
JR|Bellen, Taylor, 2001
PG|111
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144615	AU 1 Montalta-He et al.	YR 1 2001	TP 1 Abstract	TI 1 Evolutionary conservation of otd/OTX2 transcription factor action: A full genome functional genomic analysis.	REFM 1 Bellen, Taylor, 2001: 85		
ID|FBrf0144615
TP|abstract
|Drosophila meeting abstract
MABST|The evolution of the vertebrate and invertebrate CNS structrues and the
| molecular mechanisms involved are key questions in developmental biology.
| The Drosophila homeobox gene, orthodenticle, and its vertebrate homolog,
| Otx1/ 2, are required for the early patterning of the most anterior part of
| the brain and the body. Recent experiments have shown that human OTX1/ OTX2
| genes under heat-shock control can rescue the CNS defect caused by the fly
| otd mutation and otd gene introduced into the murine Otx1/ 2 locus also
| restores most of the developmental abnormalities of the mutant brain. It is
| implied that there might be a similar molecular pathway which controls the
| development of the brain in vertebrates and invertebrates, which means the
| same subset of target genes might be regulated during the cross-phylum
| functional genetic rescues. In order to examine this hypothesis, we
| ubiquitously expressed the fly otd gene and the human homolog, OTX2, under
| heat-shock control in Drosophila. High density oligonucleotide arrays
| representing the whole Drosophila genome were then used to compare the gene
| expression profiles of stage 10-17 embryos in both cases. With highly
| stringent filter criteria, we found that 287 anotated genes were regulated
| by otd overexpression of which 63 genes are functionally known while 682
| anotated genes were regulated by OTX2 overexpression which included 184
| functionally known genes. There were 93 genes which were regulated by both
| otd and OTX2. Our findings represent the first step towards identifiying a
| concerved molecular genetic network for brain development which was
| established before the diversification of the protostome and the
| deuterostome lineage during metazoan evolution.
AU|Montalta-He
|H.
AU|Leemans
|R.
AU|Loop
|T.
AU|Strahm
|M.
AU|Certa
|U.
AU|Reichert
|H.
YR|2001
TI|Evolutionary conservation of otd/OTX2 transcription factor action: A full genome functional genomic analysis.
JR|Bellen, Taylor, 2001
PG|85
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144616	AU 1 Montana and Littleton	YR 1 2001	TP 1 Abstract	TI 1 Genetic and molecular identification of novel syntaxin interacting proteins.	REFM 1 Bellen, Taylor, 2001: 37		
ID|FBrf0144616
TP|abstract
|Drosophila meeting abstract
MABST|Membrane trafficking in eukaryotic cells requires interactions between
| vesicular (v-SNAREs) and target (t-SNAREs) membrane proteins. The
| subcellular distribution and differential binding specificity of these
| proteins are thought to define both organelle identity and vesicular
| targeting. In Drosophila, the t-SNARE syntaxin 1A is essential for both
| synaptic transmission and Golgi-plasma membrane vesicle trafficking. We
| have utilized both genetic and biochemical techniques to identify new
| molecular components that interact with syntaxin. Genetic suppressor/
| enhancer screens with a temperature-sensitive allele of syntaxin (syx3-69)
| have revealed interactions with the exocytotic proteins ROP and
| synaptotagmin. Surprisingly, syx3-69 also shows interactions with mutations
| in the a -subunit of the sodium channel (para) as well. In vitro binding
| assays demonstrate a direct interaction between the cytoplasmic loop
| separating I-6 and II-1 of para with syntaxin. The genetic interactions
| between para and syntaxin suggest syntaxin is important in the regulation
| of sodium channel function, in addition to its characterized roles in the
| regulation of calcium, potassium, and the cystic fibrosis chloride
| channels. Through the use of yeast two-hybrid screens, we have also
| identified five new syntaxin-binding proteins biochemically. These include
| a homologue of SNAP-29, a novel decarboxylase and three coiled-coil
| proteins that we term SIP1, SIP2, and SIP3 (Syntaxin Interacting Protein).
| SIP1 is a 76 amino acid protein with high evolutionary conservation. This
| protein forms complexes with both itself and syntaxin and may be important
| for membrane trafficking. We will present our current analysis of these
| novel syntaxin-interacting proteins.
AU|Montana
|E.S.
AU|Littleton
|J.T.
YR|2001
TI|Genetic and molecular identification of novel syntaxin interacting proteins.
JR|Bellen, Taylor, 2001
PG|37
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144617	AU 1 Moore and Jan	YR 1 2001	TP 1 Abstract	TI 1 The hamlet gene is required for cell fate determination in the Drosophila peripheral nervous system.	REFM 1 Bellen, Taylor, 2001: 13		
ID|FBrf0144617
TP|abstract
|Drosophila meeting abstract
MABST|The newly identified hamlet gene is required for correct cell fate
| determination in the external sensory organ lineage of Drosophila. The
| Drosophila embryonic external sensory organ arises from a single Sensory
| Organ Precursor cell (SOP) that undergoes a stereotypical series of
| asymmetric cell divisions. The IIA cell daughter of the SOP divides to give
| an external sensory cell (trichogen) and a socket cell. The IIB cell
| daughter gives rise to a Multiple Dendritic (MD) neuron and the IIIB cell
| that in turn divides to give a sensory neuron and glia 1 . In hamlet
| embryos the fate of the IIIB cell daughters are altered, the sensory neuron
| is converted to a second MD neuron and the glia becomes a second trichogen.
| These transformations are unique because one IIIB cell daughter is of the B
| lineage (MD neuron) and the other of the A lineage (trichogen). In
| contrast, mutants in the numb/ notch pathway give rise to cell fate
| transformations only within the A lineage or the B lineage but not between
| them. In the Drosophila embryo, hamlet is expressed exclusively in the
| peripheral nervous system. It encodes a protein with two distinct domains
| of multiple zinc fingers and has homology to genes required for nervous
| system development in c. elegans and mammals. This similarity suggests an
| evolutionary conservation of function at the molecular level and in nervous
| system cell determination. The function of hamlet in the IIB cell lineage
| will be discussed. 1 Orgogozo et al. (2001) Development 128, 631-643.
AU|Moore
|A.W.
AU|Jan
|Y.N.
YR|2001
TI|The hamlet gene is required for cell fate determination in the Drosophila peripheral nervous system.
JR|Bellen, Taylor, 2001
PG|13
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144618	AU 1 Morimoto et al.	YR 1 2001	TP 1 Abstract	TI 1 Retrograde signaling in the development of synapses: Involvement of CaMKII in the maturation of presynaptic function.	REFM 1 Bellen, Taylor, 2001: 229		
ID|FBrf0144618
TP|abstract
|Drosophila meeting abstract
MABST|Bidirectional communication between a neuron and its postsynaptic cell is
| essential for the development and modulation of synapses. A number of
| factor, including target derived factors, regulate these processes. To
| clarify the molecular mechanism for synaptogenesis regulated by the
| target-derived factor, we investigated the effect of the modulation of
| calmodulin kinase II (CaMKII) pathway in the postsynaptic target cell on a
| synaptic transmission. Using UAS-GAL4 expression system in Drosophila
| first-instar larval neuromuscular junctions, we expressed constitutive
| active form of CaMKII (a-CaMKII) in specific muscle cells continuously from
| the early developmental stage. By the expression of a -CaMKII, the mean
| amplitude of evoked synaptic currents (ESCs) was increased in the larva jus
| t after hatching, suggesting that activation of CaMKII promotes maturation
| of the synapse. Interestingly, the mean amplitude of ESCs was reduced in
| the larva more than 4 hours after hatching which kept expressing a -CaMKII.
| This may suggest that inactivation of CaMKII is required for the further
| growth of synapses. Mean amplitude of spontaneous synaptic currents was not
| significantly different in both larvae, suggesting that the effect was
| mainly on the presynaptic mechanisms. These results suggest that
| postsynaptic CaMKII modulates maturation of the presynaptic function during
| synaptogenesis and the mode of this modulation may change during the
| development of the synapse. Supported by a Grant-in-Aid for Scientific
| Research on Priority Areas (c)-Advanced Brain Science Project-from Ministry
| of Education, Science, Sports and Culture, Japan
AU|Morimoto
|T.T.
AU|Kazama
|H.
AU|Nose
|A.
YR|2001
TI|Retrograde signaling in the development of synapses: Involvement of CaMKII in the maturation of presynaptic function.
JR|Bellen, Taylor, 2001
PG|229
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144619	AU 1 Murray et al.	YR 1 2001	TP 1 Abstract	TI 1 DFER: A cytoplasmic tyrosine kinase involved in neural development and dorsal closure.	REFM 1 Bellen, Taylor, 2001: 230		
ID|FBrf0144619
TP|abstract
|Drosophila meeting abstract
MABST|Experiments in a number of developmental contexts have suggested that the
| first neurons to extend axons in the embryo, the pioneer neurons, may
| express guidance factors that endow them with navigational capabilities not
| possessed by later developing neurons. To identify genes involved in the
| guidance of pioneer neurons we used plasmid rescue to map the insertion
| site of several pioneer neuron GAL4 driver lines. One of these expresses
| GAL4 in a subset of neurons per hemisegment, including aCC, RP2 and the
| longitudinal pioneer pCC. In this line, the pGawB P-element is inserted
| 72bp upstream of the first exon of Dfer, a member of the FES/ FPS/ FER
| family of cytoplasmic tyrosine kinases. These proteins are characterised by
| a unique N-terminal domain, an SH2 domain and a kinase domain. Vertebrate
| FER has been implicated in EGFR signalling and regulation of cadherin and
| integrin based adhesion. In the CNS, Dfer mRNA is expressed in an analogous
| pattern to the GAL4 driver. In addition, Dfer mRNA is enriched in the
| leading edge cells of the dorsal epidermis. We isolated 30 lethal mutations
| by imprecise excision and male recombination. In one of these lines,
| homozygous mutant embryos exhibit defects in both CNS development and
| dorsal closure. In the CNS, the midline spacing between the longitudinal
| connectives is reduced, and axon bundles occasionally cross the midline.
| Mutants still express Dfer mRNA and protein, and the severity of the
| midline crossing defects can be enhanced by additional expression of
| wildtype DFER. These results suggest that we have isolated a
| gain-of-function mutant. We are currently testing for genetic interactions
| with known mutants affecting both midline guidance and dorsal closure.
AU|Murray
|M.J.
AU|Hayward
|N.M.
AU|Brand
|A.H.
YR|2001
TI|DFER: A cytoplasmic tyrosine kinase involved in neural development and dorsal closure.
JR|Bellen, Taylor, 2001
PG|230
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144620	AU 1 Murthy et al.	YR 1 2001	TP 1 Abstract	TI 1 Sec5 mutations and the synaptic role of the Drosophila exocyst complex.	REFM 1 Bellen, Taylor, 2001: 38		
ID|FBrf0144620
TP|abstract
|Drosophila meeting abstract
MABST|Many components of exocytosis in yeast also have essential roles in
| neurotransmitter release. The yeast exocyst complex is localized to sites
| of membrane addition and required for exocytosis. Although the complex is
| present in the cells of higher organisms, its significance to the nervous
| system remains uncertain. The targeting of synaptic vesicles to the active
| zone is an essential feature of the synapse. It has been hypothesized that
| the exocyst spatially defines release sites and may also be required for
| vesicle fusion. Alternatively, it has been suggested that the complex is
| required for synaptic development but not for transmitter release. We are
| using Drosophila to resolve questions about the role of the exocyst complex
| in synaptic development and function. For one member of the Drosophila
| exocyst complex, sec5, we have obtained 2 EMS alleles, one null and one
| hypomorph. When mitotic recombination was used to make the eye precursor
| cells completely homozygous for either sec5 allele, no eye developed.
| Clonal analysis also indicated a requirement for sec5 in ovarian
| development. While sec5 is thus likely required for cell viability, null
| mutants live to the late first instar stage of larval development. Their
| survival is probably due to persistent maternal contribution, observed with
| monoclonal antibodies generated against Sec5. The exocyst complex and
| syntaxin are thought, by genetic analysis in yeast, to interact and, like
| sec5, syntaxin clones in the fly are cell lethal. Their zygotic phenotypes,
| however, are surprisingly distinct. Whereas in syntaxin null mutants
| synapses form but no transmitter release is observed (Schulze et al. Cell
| 80( 2): 311-20), sec5 null mutants were mobile and showed only a 46%
| reduction in the amplitude of the epsc relative to wildtype at 48 hours
| after egg laying. Though the sec5 null larvae do not substantially grow,
| they can live for up to 96 hours after egg laying. We have observed
| synaptic transmission to persist largely unaltered during this period,
| despite the significant decline of the maternal protein. Presently we are
| quantitatively comparing epsc amplitude, bouton number and size, and muscle
| size throughout larval development, to examine more closely the
| significance of the exocyst complex for transmitter release and synapse
| formation. The observed persistence of synaptic transmission supports the
| hypothesis that sec5 is not essential for mature synaptic function,
| although the physiological significance of any remaining maternal
| contribution must still be considered. The role and distribution of sec5 in
| polarized cells outside of the nervous system is also under investigation.
AU|Murthy
|M.
AU|Scheller
|R.H.
AU|Schwarz
|T.L.
YR|2001
TI|Sec5 mutations and the synaptic role of the Drosophila exocyst complex.
JR|Bellen, Taylor, 2001
PG|38
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144621	AU 1 Scott and Nash	YR 1 2001	TP 1 Abstract	TI 1 Anethesia mutants reveal the functional significance of a novel ion channel.	REFM 1 Bellen, Taylor, 2001: 39		
ID|FBrf0144621
TP|abstract
|Drosophila meeting abstract
MABST|Administration of volatile general anesthetics (VGAs) is a simple and
| effective way to perturb the nervous system of the fruit fly. A screen for
| mutants with abnormal responses to the VGA halothane thus might identify
| genes that are important for neural function. Of particular interest in
| this regard is a set of mutants called har (for halothane resistance),
| which map to the 12E region and fail to complement one another. These
| mutants not only have strong (and similar) phenotypes in virtually all
| assays of halothane sensitivity but show altered motor performance even in
| the absence of VGAs, implying that the affected gene has a significant
| physiological function in the fly. We have now identified this gene as a
| novel ion channel. The superfamily of ion channels that includes
| voltage-gated sodium and calcium channels consists of proteins with four
| repeated domains, each characterized by six membrane-spanning segments.
| Within this superfamily, genome sequencing identified a group of related
| outliers, represented by two genes in C. elegans and a single gene in D.
| melanogaster; homologous members of this family have also been identified
| in vertebrates. Although all are easily recognizable in silico as four
| domain channels, the sequences of their presumptive pore loops, voltage
| gating segments and intracellular modulatory domains are distinctive,
| implying a special function for this family. The 12E region anesthesia
| mutations, single base changes that induce either a subtle alteration in
| splicing of the gene or a modest change in an encoded TM segment, represent
| a powerful way to study the function of this unique channel. Ongoing
| studies examine its influence on the cellular physiology of the adult fly
| (via the ERG) and the larva (via the neuromsucular juction). The anatomical
| distribution of this channel is being defined using an antibody raised to
| part of the ORF.
AU|Scott
|R.L.
AU|Nash
|H.A.
YR|2001
TI|Anethesia mutants reveal the functional significance of a novel ion channel.
JR|Bellen, Taylor, 2001
PG|39
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144622	AU 1 Ng et al.	YR 1 2001	TP 1 Abstract	TI 1 Differential requirement of Rac GTPases in axon growth, guidance and branching.	REFM 1 Bellen, Taylor, 2001: 231		
ID|FBrf0144622
TP|abstract
|Drosophila meeting abstract
MABST|Growth, guidance and branching of axons are all essential for the precise
| wiring of the nervous system. How similar are the growth cone cytoskeletal
| bases that underlie these events? Rho GTPases transduce extracellular
| signals to regulate the actin cytoskeleton. In particular, Rac has been
| implicated in axon growth and guidance through studies using dominant
| mutants (Luo L, Nature Rev. Neurosci. 2000 Dec; 1 (3) 173-80). The
| functions of endogenous Rac in neuronal development have not been reported
| due to the lack of Rac mutants, the existence of multiple Rac GTPases, and
| their potential pleiotropic functions. Here we analyze the loss-of-function
| phenotypes of multiple Rac GTPases in the Drosophila mushroom body (MB)
| neurons. We show that Drosophila Rac1, Rac2 and Mtl work together to ensure
| the fidelity of MB axon growth, guidance and branching. These processes
| require an increasing amount of Rac GTPases activity and appear to use
| different effector pathways. Mosaic analyses reveal both cell autonomous
| and strikingly non-cell autonomous functions for Rac GTPases. These results
| demonstrate the central role of Rac GTPases in multiple aspects of axon
| development in vivo, and suggest that growth, guidance and branching of the
| growth cone are co-ordinated via regulation of Rac GTPases and their
| distinct effector pathways.
AU|Ng
|J.
AU|Nardine
|T.
AU|Harms
|M.
AU|Tzu
|J.
AU|Goldstein
|A.
AU|Dietzl
|G.
AU|Sun
|Y.
AU|Dickson
|B.J.
AU|Luo
|L.
YR|2001
TI|Differential requirement of Rac GTPases in axon growth, guidance and branching.
JR|Bellen, Taylor, 2001
PG|231
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144623	AU 1 Nilsen	YR 1 2001	TP 1 Abstract	TI 1 A neuronal over-expression screen for functional decline in adult flies.	REFM 1 Bellen, Taylor, 2001: 73		
ID|FBrf0144623
TP|abstract
|Drosophila meeting abstract
MABST|This experiment makes use of an established collection of stocks (EP lines)
| that up-regulate transcription of genes via GAL4/ UAS system. A strong
| neuron specific driver line is used to up -regulate transcription of the
| gene( s) downstream the EP line P-element insertion. Cohorts of over
| -expressing flies were aged to 20-30 days old and subjected to a battery of
| assays, designed to test both their behavior and physiology. We were also
| able to catalog insertions that affect behavior and viability. We postulate
| that aspects of behavior will correlate with physiological age; a change in
| the rate of functional decline may affect the rate of aging. Hence the
| primary goal is identification of insertions that may affect the rate of
| aging in adult Drosophila.
AU|Nilsen
|S.
YR|2001
TI|A neuronal over-expression screen for functional decline in adult flies.
JR|Bellen, Taylor, 2001
PG|73
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144624	AU 1 Nino-Rosales et al.	YR 1 2001	TP 1 Abstract	TI 1 Mushroom body expressed (mub) gene as a suppressor of SCA1 neurodegeneration in Drosophila.	REFM 1 Bellen, Taylor, 2001: 195		
ID|FBrf0144624
TP|abstract
|Drosophila meeting abstract
MABST|Our laboratory has established a Drosophila model system for one of the
| human neurodegenerative diseases, spinocerebellar ataxia type 1( SCA1). We
| recently used this model to screen a collection of P and EP elements
| searching for modifiers of a phenotype produced when a mutant SCA1
| transgene is overexpressed in the eye. We are currently investigating the
| most powerful suppressors recovered in the screens. Among the strong
| suppressors is a gene called mushroom body expressed (mub). The function of
| mub is unknown, but it encodes a protein containing three KH domains that
| are presumably RNA binding domains. To gain insight into the mechanism by
| which mub suppresses SCA1-induced neurodegeneration we are investigating
| its structure, expression and function. The results of this experiments
| will be presented.
AU|Nino-Rosales
|M.L.
AU|Rincon-Limas
|D.E.
AU|Botas
|J.
YR|2001
TI|Mushroom body expressed (mub) gene as a suppressor of SCA1 neurodegeneration in Drosophila.
JR|Bellen, Taylor, 2001
PG|195
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144625	AU 1 Nitz et al.	YR 1 2001	TP 1 Abstract	TI 1 Rest/activity correlates of mushroom body local field potentials in Drosophila.	REFM 1 Bellen, Taylor, 2001: 40		
ID|FBrf0144625
TP|abstract
|Drosophila meeting abstract
MABST|In mammals, clearly recognizable changes in pattern and amount of brain
| electrical activity accompany changes in motor activity and arousal
| thresholds. It has recently been demonstrated that Drosophila melanogaster
| exhibit a sleep-like state (Hendricks et al., 1999; Shaw et al., 1999).
| This state is characterized by motor inactivity and heightened arousal
| thresholds. We sought to determine whether changes in brain activity
| patterns in Drosophila are, as in mammals, closely associated with changes
| in motor activity. The thorax and head of 4, 2-4 day old, female, Canton-S
| Drosophila were fixed to a small loop of tungsten rod. One glass
| microelectrode, 10 micrometers wide at the tip, was inserted into each
| optic lobe (OL) and another through the ocelli, to rest near the mushroom
| bodies (MB). A ground wire (12 micrometer nichrome) was placed in the
| thorax. The preparation allowed free movement of limbs, abdomen, wings and
| proboscis with the animal suspended from the tungsten loop. Motor activity
| was assessed by measuring interruption of an infrared light source by limb
| movements. Recordings of local field potentials (LFPs) in the virtual
| absence of movement and power-source artifacts were achieved by current
| amplification of signals, grounding of the animal, and a Faraday cage. The
| data presented herein are from differential recordings of the MB referenced
| to an OL wire. All animals exhibited a background of low-voltage fast
| activity 40 microvolts in amplitude interrupted, with varying frequency, by
| sharp field potentials (hereafter termed 'spikes') between 50 and 200
| microvolts in amplitude and 5-50 ms in duration. Spikes were both positive
| and negative-going, and occurred in isolation as well as in bursts. These
| spikes were not caused by movement artifact since: 1. visual inspection
| indicated that these spikes could occur in the total absence of movement;
| 2. point-to-point correlation of rectified field-potential amplitude with
| movement was low. 3. spikes could still be observed in mutant animals (N=
| 3) where reversible suppression of motoneuron synaptic transmission
| produced temporary paralysis. Conversely, potent suppression of spikes
| occurred in the presence of continued movement in mutant animals (N= 3)
| where synaptic transmission of MB neurons was reversibly suppressed. Each
| animal exhibited several long (&gt; 5 minutes ) periods of motor activity
| and inactivity. We compared LFPs recorded during active periods with those
| of inactive periods using power spectral analysis and by counting the
| occurrence of spikes larger than 50 microvolts in amplitude. Spectral power
| at frequencies between 10 and 100 Hz and spike frequency decreased during
| long periods of motor inactivity. Similar observations were made in
| experiments where flies were anesthetized with carbon dioxide and during
| heat-induced paralysis of para mutants. No other correlation between LFPs
| and activity state could be discerned. Ongoing experiments aimed at
| characterizing LFPs recorded in other brain regions such as the superior
| protocerebrum and sub-esophageal ganglion may reveal different brain
| activity correlates of rest/ activity states. These results show that LFPs
| can be recorded from the brain of Drosophila and that such potentials are
| modulated by behavioral state. It remains to be determined whether the drop
| in spike-like field potentials during long inactive periods results from a
| generalized decrease in neuronal activity or a loss of synchronized MB
| neuronal activity.
AU|Nitz
|D.A.
AU|van Swinderen
|B.
AU|Tononi
|G.
AU|Greenspan
|R.J.
YR|2001
TI|Rest/activity correlates of mushroom body local field potentials in Drosophila.
JR|Bellen, Taylor, 2001
PG|40
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144626	AU 1 Norga et al.	YR 1 2001	TP 1 Abstract	TI 1 Analysis of neurodevelopmental quantitative trait loci (QTL) in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 156		
ID|FBrf0144626
TP|abstract
|Drosophila meeting abstract
MABST|In our quest for novel neurodevelopmental genes, we are determining the
| molecular basis of variation in bristle number, a quantitative trait in the
| fruitfly. Thereto we have determined the insertion sites of a collection of
| 48 single P[ lArB] insertion lines, previously generated by Lyman et al.
| (1) in a screen for mutants that consistently show a small number of extra
| or fewer bristles than the inbred parental strain. Database analysis
| reveals that, out of the 48 flanking insertions sequenced, 30 insertion
| sites map to known genes. Several of these (Delta, sca, emc, hairy,
| pointed, lola), are known to genetically interact with Notch. Others have
| been implicated earlier in peripheral nervous system development by virtue
| of their phenotype (escargot, nebbish). Twelve insertion sites target novel
| genes. Six insertion sites have not been identified. Homology searches for
| the uncharacterized targetted genes reveal two novel groups of modifiers:
| one class consists of Drosophila members of the ubiquitin-proteasome
| pathway. Another group bears homology to different steps of the
| carbohydrate modification pathway. Experiments are currently in progress to
| generate lethal loss -of-function alleles. Preliminary results suggest that
| several embryonic lethal alleles show severe neurodevelopmental defects.
| Further phenotypic and functional analyses of these mutants are in
| progress. (1) LYMAN, R. F., F. LAWRENCE, S. V. NUZHDIN and T. F. MACKAY,
| 1996 Effects of single P-element insertions on bristle number and viability
| in Drosophila melanogaster. Genetics 143: 277-292.
AU|Norga
|K.K.
AU|Patel
|P.H.
AU|Mackay
|T.F.C.
AU|Bellen
|H.J.
YR|2001
TI|Analysis of neurodevelopmental quantitative trait loci (QTL) in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|156
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144627	AU 1 Odden and Doe	YR 1 2001	TP 1 Abstract	TI 1 A conserved mechanism for motoneuron development? The role of DHB9 in specifying motoneuron fate and ventral axon projections.	REFM 1 Bellen, Taylor, 2001: 157		
ID|FBrf0144627
TP|abstract
|Drosophila meeting abstract
MABST|The Drosophila embryonic CNS consists of glia, motoneurons, interneurons and
| neurosecretory cells. We are interested in genes required for motoneuron
| development and differentiation in Drosophila. Within the vertebrate CNS,
| the characterized homeobox 9 (HB9) homologues--chick (HB9 and MNR2) and
| mouse (HB9)� are thought to be expressed exclusively in motoneurons,
| although other homologues may exist within these organisms. The HB9 knock
| out mouse has "motoneurons" that transiently express interneuron markers
| and have axon targeting defects. This suggests vertebrate HB9 is necessary
| to suppress aspects of interneuron fate, thus allowing motoneuron
| differentiation. We have identified a Drosophila homologue of HB9/ MNR2,
| cloned a full length cDNA and raised antibodies to the protein. We have
| provisionally named it Drosophila HB9 (DHB9). Within the CNS, DHB9 is
| bilaterally expressed in the nuclei of a small number of cells, many of
| which we have identified as motoneurons. DHB9 is not co-expressed with Eve,
| a marker for dorsally projecting motoneurons, but it is co-expressed with
| Islet, a marker for many ventrally projecting motor projections. In
| addition, HB9 is expressed in at least three identified interneurons: EW1,
| EW2 and EW3 of the neuroblast 7-3 lineage. Misexpression of DHB9 using the
| UAS/ GAL4 system causes a thickening of ventral motor projections (but not
| dorsal motor projections), defects in longitudinal connectives and collapse
| of commissures. These data support a role for DHB9 in the development or
| differentiation of ventrally projecting motoneurons, and raise the
| possibility of a positive function in a subset of interneurons. We are
| currently pursuing homologous recombination and mutagenesis to generate
| mutant alleles of DHB9; progress on the loss of function phenotype of DHB9
| will be presented.
AU|Odden
|J.
AU|Doe
|C.Q.
YR|2001
TI|A conserved mechanism for motoneuron development? The role of DHB9 in specifying motoneuron fate and ventral axon projections.
JR|Bellen, Taylor, 2001
PG|157
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144628	AU 1 O'Dowd	YR 1 2001	TP 1 Abstract	TI 1 AChR- and GABAR-mediated synaptic transmission in adult brain neurons in culture.	REFM 1 Bellen, Taylor, 2001: 41		
ID|FBrf0144628
TP|abstract
|Drosophila meeting abstract
MABST|Functional assessment of synaptic transmission and plasticity in Drosophila
| has relied primarily on studies at the NMJ, a peripheral glutamatergic
| synapse. Recent work in our lab has demonstrated that embryonic cultures
| can be used to examine the properties of transmission at central synapses.
| Fast excitatory synaptic transmission between cultured neurons is mediated
| by nAChRs and GABARs. We have also shown that cAMP-regulates plasticity at
| excitatory cholinergic synapses in embryonic neurons. To further explore
| molecular mechanisms important in regulating transmission between neurons
| mediating specific behaviors, such as learning and memory, we have begun
| electrophysiological analysis of adult brain neurons. Neurons obtained from
| the brains of Drosophila pupae, harvested after the major anatomical
| structures of the brain have formed, regenerated processes when grown in
| dissociated cell culture. The cultured neurons expressed voltage-gated Na +
| , Ca ++ , and K + channels and some were electrically excitable. In
| addition, spontaneously active synaptic connections, mediated by nAChRs and
| GABARs, formed between these neurons. Sub-populations of live neurons were
| identified on the basis of GFP expression in cultures prepared from brains
| of pupae from a variety of GAL4 enhancer trap lines crossed to flies
| carrying a UAS-GFP transgene. A population of GFP-positive neurons with
| small cell bodies (2-5 um) were observed in cultures prepared from the
| 107-GAL4 line which exhibits prominent GFP expression in mushroom body
| neurons in vivo. GFP-positive neurons in cultures prepared from the
| Cha-GAL4 line, in which GFP is expressed in cholinergic neurons in the
| animal, were varied in size with some as large as 10 um. These cultures
| will be used to determine the properties of cholinergic and GABAergic
| synaptic transmission in identified populations of adult brain neurons.
| (Supported by NIH grant NS27501 to DOD).
AU|O'Dowd
|D.K.
YR|2001
TI|AChR- and GABAR-mediated synaptic transmission in adult brain neurons in culture.
JR|Bellen, Taylor, 2001
PG|41
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144629	AU 1 Razzaq et al.	YR 1 2001	TP 1 Abstract	TI 1 Amphiphysin is required for organization of the excitation-contraction coupling machinery of muscles, but not for synaptic vesicle endocytosis in Drosophila.	REFM 1 Bellen, Taylor, 2001: 42		
ID|FBrf0144629
TP|abstract
|Drosophila meeting abstract
MABST|Amphiphysin 1 and 2 are enriched presynaptically in the mammalian brain and
| are proposed to recruit dynamin to sites of endocytosis. Shorter
| amphiphysin 2 splice variants are also found ubiquitously, with an
| enrichment in skeletal muscle. Surprisingly, at the Drosophila larval
| neuromuscular junction, amphiphysin is localised postsynaptically, and
| amphiphysin mutants have essentially normal neurotransmission. Amphiphysin
| mutant flies are viable, but flightless. Like a muscle -enriched isoform of
| mammalian amphiphysin 2, Drosophila amphiphysin does not bind clathrin but
| can tubulate lipids, and confocal and electron microscopy suggest that it
| is localised on T-tubules. Amphiphysin mutants have a novel phenotype, a
| severely disorganised T-tubule/ sarcoplasmic reticulum system. We therefore
| propose that muscle amphiphysin is not involved in clathrin-mediated
| endocytosis, but in the structural organisation of the membrane-bound
| compartments of the excitation-contraction coupling machinery of muscles.
AU|Razzaq
|A.
AU|Robinson
|I.M.
AU|McMahon
|H.T.
AU|Skepper
|J.N.
AU|Su
|Y.
AU|Jackson
|A.P.
AU|Gay
|N.J.
AU|O'Kane
|C.J.
YR|2001
TI|Amphiphysin is required for organization of the excitation-contraction coupling machinery of muscles, but not for synaptic vesicle endocytosis in Drosophila.
JR|Bellen, Taylor, 2001
PG|42
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144630	AU 1 Orem and Dolph	YR 1 2001	TP 1 Abstract	TI 1 Endocytosis of persistant rhodopsin-arrestin complexes as a mechanism for light-dependent retinal degeneration.	REFM 1 Bellen, Taylor, 2001: 196		
ID|FBrf0144630
TP|abstract
|Drosophila meeting abstract
MABST|Mutations in a retinal-specific Phospholipase C (norpA) undergo massive
| retinal degeneration in five days of constant light. We have shown that
| this form of retinal degeneration is characterized by the apoptotic death
| of the photoreceptor cells. Additionally, we have shown that in norpA
| alleles persistent rhodopsin-arrestin complexes are formed and that these
| complexes are a critical factor in norpA mediated retinal degeneration.
| Furthermore, inhibiting apoptosis or receptor-mediated endocytosis can
| block this degeneration. We now demonstrate using biochemistry and
| immunohistochemistry that the rhodopsin-arrestin complexes are quickly
| removed from the rhabdomere in light treated norpA flies, and that this
| endocytosis causes the rapid degradation of rhodopsin, but arrestin remains
| stable. Furthermore, by examining mutants in the endocytic pathway we have
| shown that receptor mediated endocytosis is necessary for the
| internalization phenotype and is a critical process in norpA mediated
| retinal degeneration. By using a combination of genetic, biochemical, and
| immunohistological techniques we hope to further dissect how the
| endocytosis of persistent rhodopsin-arrestin complexes leads to apoptotic
| death of the photoreceptor cell.
AU|Orem
|N.
AU|Dolph
|P.
YR|2001
TI|Endocytosis of persistant rhodopsin-arrestin complexes as a mechanism for light-dependent retinal degeneration.
JR|Bellen, Taylor, 2001
PG|196
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144631	AU 1 Osterwalder et al.	YR 1 2001	TP 1 Abstract	TI 1 A GAL4/UAS based system for conditional, tissue-specific transgene expression.	REFM 1 Bellen, Taylor, 2001: 83		
ID|FBrf0144631
TP|abstract
|Drosophila meeting abstract
MABST|The most widely used system for spatially restricted transgene expression in
| Drosophila is based on the yeast GAL4 protein and its target upstream
| activating sequence (UAS). To permit temporal as well as spatial control
| over UAS-transgene expression, we have explored the use of a conditional,
| RU486 dependent GAL4 protein (GeneSwitch GAL4) in Drosophila. Using cloned
| promoter fragments of the embryonic lethal abnormal vision (ELAV) gene, or
| the myosin heavy chain (MHC) gene, we have expressed GeneSwitch GAL4
| specifically in larval neurons or muscles and show that its transcriptional
| activity within the target tissues depends upon the presence of the
| activator RU486 (mifepristone). We have furthermore generated two enhancer
| detector constructs for GeneSwitch GAL4 and used these to generate randomly
| inserted P-Element lines that express reporter constructs in an RU486
| dependent fashi on in different cellular subsets in the adult head. Target
| tissue specific reporter protein expression could be detected within hours
| after systemic application of RU486. Transgene expression levels were
| dose-dependent on RU486 concentration in the food, with low background
| expression in the absence of RU486. Using MHC-GeneSwitch GAL4 in
| combination with a genetically altered ion channel (UAS-EKO), we were able
| to change the physiological properties of larval bodywall muscles in an
| RU486 dependent fashion. Using enhancer detector lines that drive
| expression in adult fat bodies, we could ablate fat body cells with
| diphtheria toxin and produce female sterility and eventual adult lethality.
| Thus, we have demonstrated the applicability of GeneSwitch GAL4 for
| conditional, tissue specific expression in Drosophila during development
| and in adult flies. With ELAV-GeneSwitch GAL4 and MHC-GeneSwitch GAL4, we
| provide tools to temporally control pre-and postsynaptic expression of
| transgenes at the larval neuromuscular junction, and with the GeneSwitch
| GAL4 enhancer detector lines, we can conditionally express UAS-transgenes
| in subsets of adult neurons.
AU|Osterwalder
|T.P.
AU|Roman
|G.
AU|Yoon
|K.
AU|White
|B.H.
AU|Davis
|R.L.
AU|Keshishian
|H.
YR|2001
TI|A GAL4/UAS based system for conditional, tissue-specific transgene expression.
JR|Bellen, Taylor, 2001
PG|83
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144632	AU 1 Orlichenko et al.	YR 1 2001	TP 1 Abstract	TI 1 Genetic control of rhodopsin trafficking.	REFM 1 Bellen, Taylor, 2001: 137		
ID|FBrf0144632
TP|abstract
|Drosophila meeting abstract
MABST|Defects in rhodopsin transport triggers retinal degeneration in humans,
| other vertebrates, and Drosophila. We are characterizing the molecular
| components and processes underlying posttranslational processing and
| transport of rhodopsin. There are two major advantages of the Drosophila
| experimental system for this analysis. First, mutations in a large number
| of Drosophila genes have been generated by extensive P element mutagenesis
| efforts. Second, the phenotype of lethal genes can nonetheless be assessed
| in differentiated adult photoreceptors by use of FLP/ FRT-triggered mitotic
| recombination. Our analysis shows that delivery of rhodopsin to the
| rhabdomeric membranes of photoreceptors requires gene products coding
| general cellular components of the secretory system as well as gene
| products whose function is restricted to rhodopsin maturation. Specific
| members of the Rab and Arf family of small GTPases are components of
| secretory pathways common to all cells. Using mosaics, we show that none of
| these genes are required for photoreceptor cell viability or the
| establishment of polarized cellular compartments within these cells.
| Observations from electron microscopy, protein blotting, and GFP-labeling
| of specific cellular compartments, differentiate the effects of these genes
| on protein trafficking within the photoreceptor. Similar molecular genetic
| approaches are applicable to other lethal mutations. In one example, we
| show an essential role for the Drosophila homolog of the bacterial tetR
| transporter. Mosaic analysis revealed that photoreceptors lacking this
| transporter do not efficiently mature rhodopsin and other membrane
| proteins. Ultrastructural analysis confirmed deficits in membrane
| trafficking, and also showed that the transporter protein is normally
| localized within the ER/ Golgi compartment.
AU|Orlichenko
|L.
AU|Gu
|G.
AU|Lee
|J.
AU|Sarfare
|S.
AU|Adams
|S.
AU|Mitchell
|K.
AU|Grove
|S.
AU|O'Tousa
|J.
YR|2001
TI|Genetic control of rhodopsin trafficking.
JR|Bellen, Taylor, 2001
PG|137
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144633	AU 1 Packard et al.	YR 1 2001	TP 1 Abstract	TI 1 Genetic interaction between fasciclin II and b-amyloid precursor protein during synapse formation at the Drosophila neuromuscular junction.	REFM 1 Bellen, Taylor, 2001: 232		
ID|FBrf0144633
TP|abstract
|Drosophila meeting abstract
MABST|A central question in neurobiology is what are the mechanisms surrounding
| synapse development and functional plasticity. In an effort to broaden our
| understanding of these important processes we have been examining the roles
| of activity and cell adhesion on the development and maintenance of the fly
| larval neuromuscular junction (NMJ). Previous studies have shown an
| increase in the number of synaptic boutons contacting larval muscles at
| hyperexcitable NMJs. Bouton number is also regulated in a dose-dependent
| manner by Fasciclin II (FasII), a cell adhesion molecule of the NCAM
| family. In addition, we have previously reported that the Drosophila
| homolog of the mammalian b -Amyloid Precursor Protein (APPL) induces
| budding of synaptic sprouts and the differentiation of these sprouts into
| mature boutons. APPL overexpression in motorneurons results in a dramatic
| increase in bouton number. APPL localization has also been shown to be
| enriched at hyperexcitable NMJs. In contrast, appl mutants show a reduction
| in bouton number, a phenotype also exhibited by FasII mutants. To
| investigate how APPL and FasII functions might be coordinated to regulate
| synapse formation, we used the UAS/ Gal4 system to manipulate FasII levels
| in flies overexpressing APPL. We found that APPL-induced overgrowth was
| partially rescued when we expressed APPL in a FasII hypomorphic mutant.
| Moreover, when both proteins were simultaneously overexpressed, we found
| extraordinary morphological defects in boutons at both the light and
| ultrastructural levels. These defects include the presence of extremely
| large boutons containing an intricate system of internal membrane-bound
| structures. We further report the use of a fluorescent probe, FM 1-43, to
| visualize activity-dependent synaptic vesicle recycling in these defective
| boutons, as well as the immunolocalization of vesicular markers, budding
| bouton markers, and of proteins involved in endocytosis within the
| defective boutons. Our observations support a model by which surface APPL
| is required for initial budding of synaptic boutons, and concomitant low
| localized FasII levels are required for the elongation of nascent buds to
| form extensions between neighboring boutons.
AU|Packard
|M.
AU|White
|K.
AU|Budnik
|V.
YR|2001
TI|Genetic interaction between fasciclin II and b-amyloid precursor protein during synapse formation at the Drosophila neuromuscular junction.
JR|Bellen, Taylor, 2001
PG|232
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144634	AU 1 Paradis et al.	YR 1 2001	TP 1 Abstract	TI 1 Homeostatic control of presynaptic release is triggered by postsynaptic membrane depolarization.	REFM 1 Bellen, Taylor, 2001: 247		
ID|FBrf0144634
TP|abstract
|Drosophila meeting abstract
MABST|In the nervous system, homeostatic mechanisms exist to maintain cellular
| excitation within a precise physiological range. The mechanisms that
| initiate homeostatic changes to synaptic function are not known. To date,
| experiments at both vertebrate and Drosophila synapses have investigated
| homeostatic regulation of synaptic function by perturbing either
| presynaptic activity or postsynaptic receptor function. For example, at the
| Drosophila NMJ, impaired glutamate receptor (GluR) function is compensated
| for by an increase in presynaptic neurotransmitter release resulting in
| wild type muscle depolarization. Here we have impaired the ability of the
| synapse to depolarize postsynaptic muscle without altering GluR function.
| Expression of the Kir2.1 potassium channel in muscle impairs muscle
| excitability by inducing a persistent outward current, hyperpolarizing the
| muscle resting potential, and decreasing muscle input resistance. We
| observe a compensatory increase in presynaptic neurotransmitter release,
| which results in normal muscle depolarization despite decreased muscle
| excitability. These data demonstrate that altered membrane depolarization
| is able to initiate a homeostatic increase in presynaptic neurotransmitter
| release. The altered membrane properties of Kir2.1 expressing muscle also
| cause the EPSP to repolarize more rapidly compared to EPSPs at wild type or
| GluR mutant synapses. As a consequence, EPSPs at Kir2.1 expressing synapses
| do not summate as well as EPSPs observed in wild type or GluR mutants.
| Thus, during short trains of stimuli, Kir2.1 expressing synapses do not
| achieve the same summed depolarization compared to wild type and GluR
| mutants despite the observation that the initial EPSP amplitude of the
| stimulus train is the same comparing these three genotypes. This deficit in
| EPSP summation correlates with a decrease in the velocity of larval
| crawling. Since the first EPSP amplitude of a stimulus train is
| homeostatically regulated in both GluR mutants and Kir2.1 expressing
| synapses, yet the summated depolarization remains impaired at Kir2.1
| synapses, we hypothesize that the information utilized for the homeostatic
| regulation of synaptic function is contained within the time course of the
| first EPSP. We are currently investigating t he time course of homeostatic
| regulation and the effectors within the presynaptic nerve terminal that
| achieve enhanced presynaptic transmitter release during this phenomenon.
AU|Paradis
|S.
AU|Eaton
|B.A.
AU|Sweeney
|S.T.
AU|Davis
|G.W.
YR|2001
TI|Homeostatic control of presynaptic release is triggered by postsynaptic membrane depolarization.
JR|Bellen, Taylor, 2001
PG|247
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144635	AU 1 Parisky et al.	YR 1 2001	TP 1 Abstract	TI 1 Mutations in a rare alternative splicing event of the para Na channel confer defects in specific sensory modalities.	REFM 1 Bellen, Taylor, 2001: 43		
ID|FBrf0144635
TP|abstract
|Drosophila meeting abstract
MABST|The smellblind mutants were originally identified in screens for genetic
| defects in larval chemosensation or adult olfactory-based learning.
| Subsequently, sbl mutations were shown to be alleles of the para locus, the
| structural gene for the action potential Na channel. The sbl mutations are
| unique, in that, most para mutations confer temperature-sensitive (ts)
| paralysis and do not display olfactory defects. Likewise, sbl alleles of
| para are not ts-paralytic. We have determined that the sbl alleles of para
| are defective in the production of a particular rare alternative
| splice-form of the Na channel. The molecular lesions in all isolated sbl
| alleles are consistent with this splicing defect. The alternative splice
| choice occurs in a functionally important region of the Na channel protein
| and we provide evidence that this is an ancient and highly conserved
| regulatory event. In addition, the alternative splice decision is
| developmentally regulated. Lastly, we address the possible cell-specific
| regulation of this alternative splicing within the nervous system via
| transgenic alternative-splicing reporter constructs.
AU|Parisky
|K.
AU|Ganetzky
|B.
AU|Reenan
|R.
YR|2001
TI|Mutations in a rare alternative splicing event of the para Na channel confer defects in specific sensory modalities.
JR|Bellen, Taylor, 2001
PG|43
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144636	AU 1 Park et al.	YR 1 2001	TP 1 Abstract	TI 1 Functions for ecdysis-triggering hormone in insect ecdysis.	REFM 1 Bellen, Taylor, 2001: 197		
ID|FBrf0144636
TP|abstract
|Drosophila meeting abstract
MABST|Peptide signaling molecules play important roles in the initiation and
| performance of animal behaviors. At the end of each developmental stage,
| insects release the peptidic ecdysis-triggering hormone (ETH) to initiate a
| behavioral sequence leading to cuticle shedding. While ETH is sufficient to
| trigger ecdysis, the full scope and obligatory nature of its action has
| remained unclear. We have described a gene eth encoding ETH in Drosophila
| melanogaster. To test the hypothesis that ETH is necessary as a signal for
| ecdysis, we created eth null mutants by imprecise P-element excision. This
| mutation produces ecdysis deficiencies and the lethal phenotype
| "buttoned-up" at the transition from first to second larval instar. These
| animals show loss of the ecdysis behavioral sequence, defective respiratory
| dynamics, and failure to shed the old cuticle and old mouth hooks.
| Defective tracheal dynamics normally associated with ecdysis include
| tracheal collapse, inflation, and shedding of the old trachea. All ecdysis
| deficiencies are rescued by injection of synthetic ETH. These findings
| establish the necessary and sufficient role of eth and its gene product for
| insect ecdysis.
AU|Park
|Y.
AU|Filippov
|V.
AU|Gill
|S.S.
AU|Adams
|M.E.
YR|2001
TI|Functions for ecdysis-triggering hormone in insect ecdysis.
JR|Bellen, Taylor, 2001
PG|197
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144637	AU 1 Phillips et al.	YR 1 2001	TP 1 Abstract	TI 1 A neurological role for the product of the black gene?	REFM 1 Bellen, Taylor, 2001: 198		
ID|FBrf0144637
TP|abstract
|Drosophila meeting abstract
MABST|The black gene of Drosophila melanogaster was first identified as encoding a
| product involved in b-alanine production via the biogenic amine pathway.
| Melanization and sclerotization of the fly cuticle are abnormal in black,
| however, defects in this metabolic pathway, for example the tan and ebony
| mutations, are also known to affect neurotransmission in the visual system.
| In 1993 we reported the cloning of a gene encoding a PLP-dependent
| acidic-amino-acid decarboxylase, Dgad2, expressed in lamina glia. Enzyme
| assays on protein extracts from mutant fly heads showed minimal decreases
| in decarboxylation of glutamate and aspartate, relative to wild-type
| protein extracts, and fusion proteins expressed in bacterial cells were
| enzymatically inactive. During annotation of the Drosophila genome sequence
| Dgad2 was clearly established as the black gene. The biochemical defect in
| black mutants thus resides in aspartate decarboxylation rather than in the
| alternative uracil metabolic pathway. Therefore, black, along with tan and
| ebony has a role in the visual system and b -alanine a putative role as a
| neuromodulator in vivo. We are addressing the role of Dgad2/ black using
| the black1 mutant. We have found that there is both molecular and
| biochemical data consistent with the gene producing at least two proteins,
| probably reflecting spatial and temporal expression. The black1, mutation
| was found to be a functional null, a four base insertion causing a
| frameshift which results in a truncated protein. Western analysis of head
| extracts suggests the mutant product is degraded. Electrophysiological,
| studies are in progress. The black1 mutant shows a significant reduction in
| aspartate (but not glutamate) decarboxylation under conditions implying
| regulation of activity at the protein level. The presence of the GAD1
| protein in extracts from fly heads complicates attempts to confirm that the
| DGAD2/ black enzyme exhibits substrate specificity for aspartate. This is
| being addressed in vitro, using immunoprecipitation and fusion construct
| studies. Studies are also in progress to identify the visual system target
| of the GABA/ b-alanine product.
AU|Phillips
|A.M.
AU|Pitts
|R.S.
AU|Kelly
|L.E.
YR|2001
TI|A neurological role for the product of the black gene?
JR|Bellen, Taylor, 2001
PG|198
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144638	AU 1 Plavicki et al.	YR 1 2001	TP 1 Abstract	TI 1 Imaging distal-less expression in the living embryonic brain.	REFM 1 Bellen, Taylor, 2001: 74		
ID|FBrf0144638
TP|abstract
|Drosophila meeting abstract
MABST|The Dlx genes play critical roles in vertebrate brain development, yet the
| role( s) of their Drosophila homolog, Distal-less (Dll), in the fly brain
| remain unknown. Homologous regulatory genes have been implicated in
| regionalization, pattern formation, and identity specification during
| embryonic CNS development of vertebrates and invertebrates. Thus, providing
| precedence for the involvement of Dll in the developing fly brain.
| Immunostainings of fixed Drosophila embryos with Dll antibodies suggested
| that Dll is broadly expressed in the head ectoderm in brain precursors
| prior to their delamination and differentiation. We are using a two-photon
| microscope to create four-dimensional reconstructions of developing
| Drosophila embryos to visualize the migration of Dll expressing cells. To
| do so, we are employing a Gal4-UAS system in which the expression of a
| nuclear-localized GFP is under the control of Dll promoter elements. The
| detrimental effects of extensive laser exposure limit the use of
| conventional confocal microscopy as a means of investigating these
| processes. The less invasive nature of multiphoton microscopy enables us to
| make in vivo recordings that extend over longer periods of development
| while maintaining high levels of viability. Thus, we are able to follow the
| movements of cells through both space and time from germband extension to
| the completion of head involution. Due to the perdurance of GFP, we can
| visualize Dll-expressing cells and their progeny even when the Dll gene is
| no longer active. This provides us with a unique opportunity to follow
| cells exposed to Dll over extensive periods of development. The multiphoton
| analysis, in conjunction with immunohistochemical studies of fixed
| wild-type and Dll mutant embryos, will allow us to determine the role( s)
| of Dll in Drosophila brain development and to compare the function( s) of
| Dll to those of its vertebrate counterparts.
AU|Plavicki
|J.
AU|Squirrel
|J.
AU|White
|J.
AU|Panganiban
|G.
YR|2001
TI|Imaging distal-less expression in the living embryonic brain.
JR|Bellen, Taylor, 2001
PG|74
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144639	AU 1 Lohr et al.	YR 1 2001	TP 1 Abstract	TI 1 Studying neuron-neuron synapses of Drosophila.	REFM 1 Bellen, Taylor, 2001: 233		
ID|FBrf0144639
TP|abstract
|Drosophila meeting abstract
MABST|We are interested in mechanisms underlying the embryonic development of
| synapses. So far neuromuscular junctions (NMJs) have been used for these
| purposes. However, embryonic NMJs lack postsynaptic neuronal mechanisms and
| contain mainly one type of glutamatergic synapse. To circumvent these
| restrictions we establish embryonic neuron-neuron synapses for the study of
| synaptogenetic mechanisms. We make use of individually identifiable
| neurons, which can be studied under mutant or genetically manipulated
| conditions. To trace synapses of identified neurons in the CNS we carry out
| mosaic studies. Firstly, expression of synaptic proteins in identified
| neurons (Gal4/ Uas-system; collaboration with E. Buchner, W�rzburg) roughly
| indicates synaptic sites. However, background stain due to high levels of
| the artifically induced proteins make interpretations hard. Secondly, to
| look at the intrinsic expression and distribution of such synaptic proteins
| we raise mosaics through cell transplantations. We transplant neural
| precursors from wild type embryos expressing CD8-GFP panneuronally into
| embryos lacking specific synaptic proteins. Neurons of the resulting cell
| lineage are the only cells containing CD8-GFP (showing the cells'
| morphology) and the respective synaptic proteins (indicating synaptic
| sites). Such cell lineages show spatially restricted and reproducible
| distributions of synaptic spots on neuronal surfaces. On the one hand these
| synaptic patterns are much quicker to obtain than through ultrastructural
| serial analyses and can be used to elucidate principles of synapse
| distribution in the CNS. For example, our data suggest that many
| motorneurons have no presynaptic sites within the CNS. On the other hand,
| they can be carried out in mutant or genetically manipulated backgrounds in
| order to study mechanisms underlying synapse distribution. In order to
| study potential signal dependence of synaptic development and distribution,
| we make use of primary cell cultures. We generate our own Schneider's based
| medium and can easily change its ions contents. Under the right conditions
| synapses differentiate at the immunocytochemical, ultrastructural and
| physiological level. Making use of defined Gal4/ GFP-expressing neurons we
| have begun to compare the morphology and electrophysiology of cultured
| neurons to their counterparts in the embryonic CNS. This work is supported
| by the Deutsche Forschungsgemeinschaft (PR605/ 1-2; Te130/ 7-4)
AU|Lohr
|R.
AU|Kuppers
|B.
AU|Letzkus
|J.
AU|Technau
|G.
AU|Prokop
|A.
YR|2001
TI|Studying neuron-neuron synapses of Drosophila.
JR|Bellen, Taylor, 2001
PG|233
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144640	AU 1 Rajaram and Nash	YR 1 2001	TP 1 Abstract	TI 1 Are shaker channels in the fly eye anesthetic targets?	REFM 1 Bellen, Taylor, 2001: 44		
ID|FBrf0144640
TP|abstract
|Drosophila meeting abstract
MABST|In vertebrates, general anesthetics (GAs) cause reversible loss of
| consciousness, memory and pain sensation. In Drosophila, GAs cause
| behavioral changes at clinically comparable concentrations and several fly
| mutants with altered GA sensitivities have been isolated. To provide a more
| focused approach towards understanding the influence of these mutated genes
| on anesthesia, we are using a simple, circumscribed neural circuit that
| avoids the complexities of whole animal behavioral studies. The
| electroretinogram (ERG) is a mass potential that primarily reports on two
| cell types: the retinal photoreceptors (PRs) and the laminar large
| monopolar cells (LMCs) onto which they form inhibitory synapses. Literature
| suggests that laminar amacrine cells serve as interneurons between these
| two cell types and provide excitatory cholinergic input to the LMCs. In a
| wildtype fly, at concentrations of the GA halothane that affect behavior,
| only the Lights-Off transient response of LMCs (presumably involving the
| amacrine cells) is significantly depressed. This effect is more robust with
| short (0.2 sec) light pulses suggesting a decreased susceptibility of these
| cells to GAs following light adaptation. Amongst the mutants influencing
| the ERG or its modulation by GAs, those affecting the Shaker (Sh) K +
| channels are most prominent. Genetic (null alleles) or pharmacological
| (4-Aminopyridine) inhibition of Sh channel function reproduces the
| halothane effect on the Off transient. Although Sh expression in the PRs
| has been well documented, its function in a neural circuit affecting vision
| had been hitherto uncharacterized. Previous in vitro studies have shown
| that when expressed in Xenopus oocytes, Sh channels are partially inhibited
| by GAs. The differential sensitivity of the different Sh isoforms suggests
| that effects of GAs on these channels are subunit specific. Experiments are
| currently underway that use the appropriate combinations of cell specific
| drivers and transgenes to address the question of the cell type( s) in
| which function of specific Sh isoforms is required for the proper
| functioning of this circuit.
AU|Rajaram
|S.
AU|Nash
|H.A.
YR|2001
TI|Are shaker channels in the fly eye anesthetic targets?
JR|Bellen, Taylor, 2001
PG|44
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144641	AU 1 Rebay et al.	YR 1 2001	TP 1 Abstract	TI 1 Eyes absent mediates cross-talk between a network of retinal determination genes and the receptor tyrosine kinase signaling pathway.	REFM 1 Bellen, Taylor, 2001: 138		
ID|FBrf0144641
TP|abstract
|Drosophila meeting abstract
MABST|The eyes absent (eya) gene has been shown by multiple labs to function in an
| intricate network of "master regulatory genes" that are interdependently
| required to promote eye development. In addition to a role in promoting eye
| formation, eya is likely to have additional functions in development based
| on its complex expression pattern and the embryonic lethality of null
| mutations. We have found that Drosophila EYA function is positively
| regulated by MAPK-mediated phosphorylation and that this regulation extends
| to developmental contexts independent of eye determination. In vivo genetic
| analyses, together with in vitro kinase assay results, demonstrate that EYA
| is a substrate for ERK, the MAPK acting downstream in the receptor tyrosine
| kinase (RTK) signa ling pathway. Thus phosphorylation of EYA appears to
| provide a direct regulatory link between the RTK/ RAS/ MAPK signaling
| cascade and the retinal determination gene network. We will report the
| results of recent experiments that investigate the molecular mechanisms
| whereby ERK-mediated phosphorylation of Eya modulates its activity in
| different developmental contexts. We have noted that other members of the
| retinal determination gene network also contain MAPK phosphorylation
| consensus sites, suggesting that activity of this network could be more
| generally regulated by MAPK signaling pathways. Results of experiments
| designed to determine whether other members of the retinal determination
| network are regulated via phosphorylation by MAPK or whether EYA in fact
| represents the sole point of cross-talk will be presented.
AU|Rebay
|I.
AU|Davies
|E.
AU|Hsiao
|F.
AU|Mills
|I.
AU|Williams
|A.
YR|2001
TI|Eyes absent mediates cross-talk between a network of retinal determination genes and the receptor tyrosine kinase signaling pathway.
JR|Bellen, Taylor, 2001
PG|138
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144642	AU 1 Reeves and Posakony	YR 1 2001	TP 1 Abstract	TI 1 Gene expression profiling of proneural cluster cells to identify targets of the proneural proteins.	REFM 1 Bellen, Taylor, 2001: 75		
ID|FBrf0144642
TP|abstract
|Drosophila meeting abstract
MABST|Historically, the functions of the proneural genes of Drosophila have been
| investigated most intensively in the ectoderm. Here, expression of the
| basic helix-loop-helix (bHLH) transcriptional activators encoded by the
| proneural genes confers on cells the potential to adopt neural cell fates.
| For example, within the developing wing imaginal disc of late third-instar
| larvae, small clusters of cells express the proneural genes achaete and
| scute, and this spatially restricted pattern ultimately defines the
| positions of the mechanosensory bristles that decorate the adult thorax.
| Each bristle is composed of the progeny of a single sensory organ precursor
| selected from within a proneural cluster (PNC) by inhibitory cell -cell
| interactions mediated by the Notch pathway. Recent studies, howe ver, have
| demonstrated Notch-dependent selection of single precursor cells from
| within groups of proneural gene-expressing cells in both the mesoderm
| (muscle founder cells) and the endoderm (adult midgut precursors and
| interstitial cell precursors), suggesting a much more generalized function
| of these so -called "proneural" genes. We hypothesize, therefore, that the
| targets of transcriptional regulation by the proneural proteins may include
| both a "core" set of genes representing the general function of the se
| proteins in promoting precursor cell specification in any context, and
| "context-specific" genes expressed only in certain settings (e. g.,
| ectodermal PNCs). Overall, we believe that the potential of proneural
| gene-expressing cells to adopt a specialized cell fate is conferred by the
| particular profile of genes (of both classes) expressed in these cells and
| not in the surrounding cells. To define the specific gene expression
| profile of PNC cells, we have developed fly lines in which a reporter gene
| construct drives expression of GFP specifically in these cells.
| Fluorescence-activated cell sorting (FACS) has been used to purify PNC
| cells away from the surrounding cells in the wing imaginal disc. We are in
| the process of comparing transcript levels between these two cell
| populations using Affimetryx � high-density oligonucleotide arrays.
| Secondary screens such as in situ hybridization and binding site searches
| are used to identify bona fide genes of interest. We will report on our
| progress in this global analysis of proneural gene function.
AU|Reeves
|N.L.
AU|Posakony
|J.W.
YR|2001
TI|Gene expression profiling of proneural cluster cells to identify targets of the proneural proteins.
JR|Bellen, Taylor, 2001
PG|75
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144643	AU 1 Ren and Tanouye	YR 1 2001	TP 1 Abstract	TI 1 The jitterbug gene: A mutation in a Drosophila filamin causes seizures, synaptic failure and paralysis.	REFM 1 Bellen, Taylor, 2001: 45		
ID|FBrf0144643
TP|abstract
|Drosophila meeting abstract
MABST|Drosophila neurobiology is a powerful tool that could be used to uncover
| fundamental mechanisms underlying human neuropathic diseases. Drosophila
| mutants may be used to model idiopathic neurological disorders, and mutant
| phenotypes used to dissect apart the complex pathology that is often
| associated with human disorders. Here, we present a model for human
| periventricular heterotopia (PH): mutations of the Drosophila jitterbug
| (jbug) gene that cause bang-sensitive paralysis. Cortical malformations
| (dysplasia) are often associated with seizure and chronic epileptic
| disorders. PH is an inherited human disease that causes dysplasia, and is
| associated with epilepsy. Recently, the mutation responsible for this
| disease has been linked to the human filamin-1 (ABP-280) gene. jbug is a
| Drosophila filamin-like gene on the second chromosome (58F to 59A). A
| P-element insertion into this gene results in a mutant that is about 2 to 3
| times more susceptible to seizure than wild type. Unlike the human
| mutation, we could not find any structural or axon guidance defects in the
| embryonic, larval or adult nervous system of the P-element allele. We are
| currently examining other alleles of jbug for structural defects. The
| current hypothesis regarding the relationship between cortical dysplasia
| and epilepsy centers on the abnormal neuronal networks that form due to
| abnormal development. The possibility that intrinsic properties of mutant
| neurons may contribute to seizure genesis has been largely ignored. jbug
| allows the study of possible seizure-genic property of neurons in a filamin
| mutant without the influence of gross anatomical defects. We have examined
| the properties of jbug nervous system using the adult giant -fiber (GF) and
| the larval neuromuscular junction (LNMJ) as our assays. We have found that
| at the LNMJ miniature EPSP frequency was increased in the mutant (2.7�
| 0.5Hz) when compared to wild type (1Hz). We have not found any defects
| associated with the adult giant -fiber system. Recently, we have discovered
| that jbug is also a cold-sensitive paralytic mutation. At 10� C jbug flies
| paralyze within a minute; wild type flies are not affected for at least 5
| minutes at this temperature. Interestingly, jbug is also more susceptible
| to seizure in cold temperatures. Currently, we are examining effects of
| temperature on the adult GF and LNMJ.
AU|Ren
|X.
AU|Tanouye
|M.
YR|2001
TI|The jitterbug gene: A mutation in a Drosophila filamin causes seizures, synaptic failure and paralysis.
JR|Bellen, Taylor, 2001
PG|45
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144644	AU 1 Renden and Broadie	YR 1 2001	TP 1 Abstract	TI 1 Drosophila CAPS mediates dense core vesicle neuromodulator release and regulation of synaptic vesicle fusion.	REFM 1 Bellen, Taylor, 2001: 46		
ID|FBrf0144644
TP|abstract
|Drosophila meeting abstract
MABST|Calcium-Activated Protein for Secretion (CAPS) is proposed to play an
| essential, specific role in Ca 2+ -regulated dense core vesicle exocytosis
| in vertebrate neuroendocrine cells. The Drosophila ortholog, dCAPS, is ~60%
| identical, restricted to the nervous system, and the dCAPS protein
| localizes to neuronal synapses. Null mutants display profound locomotory
| deficits and complete embryonic lethality. Electrophysiological recordings
| at the mutant NMJ reveal ~50% reduction in evoked glutamatergic
| transmission resulting from decreased Ca 2+ -dependent exocytosis. This
| defect is not rescued by cell-autonomous transgenic expression,
| demonstrating protein function at a distinct location. dCAPS mutants also
| display a 3-fold accumulation of dense core vesicles in synaptic terminals,
| a highly specific block not observed in mutants which completely arrest
| synaptic vesicle exocytosis. The essential requirement for dCAPS is
| completely rescued by expressing the protein only in defined neurosecretory
| neurons. We conclude that CAPS is specifically required for regulated dense
| core vesicle release in both mammals and flies. We are currently developing
| functional assays to measure the release of dense core vesicle contents in
| vivo and in vitro. These approaches, involving electrophysiological and
| optical assays, will be discussed at the meeting.
AU|Renden
|R.
AU|Broadie
|K.
YR|2001
TI|Drosophila CAPS mediates dense core vesicle neuromodulator release and regulation of synaptic vesicle fusion.
JR|Bellen, Taylor, 2001
PG|46
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144645	AU 1 McBride et al.	YR 1 2001	TP 1 Abstract	TI 1 Molecular cloning, expression, and tissue distribution of two Drosophila cholecystokinin-like receptors.	REFM 1 Bellen, Taylor, 2001: 47		
ID|FBrf0144645
TP|abstract
|Drosophila meeting abstract
MABST|The cholecystokinin receptor is a member of the seven transmembrane domain
| �-adrenergic receptor superfamily. Two distinct subtypes (CCK-1R and
| CCK-2R) have been extensively characterized in mammals. These proteins
| share high affinity for the endogenous ligand cholecystokinin octapeptide
| (CCK-8). Both receptors are expressed in the CNS and in the periphery,
| where they modulate a range of physiologic functions including food intake,
| acid secretion, intestinal motility and analgesia. We have cloned two
| Drosophila CCK-receptor cDNAs (CCKR-17D1 and CCKR-17D3) by RT-PCR using
| Drosophila pupae and adult body RNA as a template. The deduced amino acid
| sequences of the Drosophila CCK-like receptors share ~ 40%-50% identity
| with each other, and with each of the mammalian CCK receptor homologs. To
| date, the endogenous ligand of the Drosophila CCK-like receptors remains
| unknown. When transfected into HEK 293 cells, neither Drosophila receptor
| cDNA appears to result in a cell surface protein. Work is in progress using
| epitope ( FLAG) tagged receptors to determine whether proper cell surface
| expression can be achieved in Drosophila Schneider-2 cells. In parallel,
| the tissue distribution of the endogenous mRNAs is being assessed by in
| situ hybridization. Whole mounts of brain, mid-and hindguts isolated from
| wild-type third instar larvae are being probed using DIG-antisense RNA to
| determine cell specific expression. These results should provide hints
| regarding the function of the Drosophila CCK-like receptors in vivo.
AU|McBride
|E.W.
AU|Reveillaud
|I.
AU|Ren
|Y.
AU|Kopin
|A.S.
YR|2001
TI|Molecular cloning, expression, and tissue distribution of two Drosophila cholecystokinin-like receptors.
JR|Bellen, Taylor, 2001
PG|47
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144646	AU 1 Reynolds et al.	YR 1 2001	TP 1 Abstract	TI 1 Human epileptic drugs reduce seizure and paralysis in easily shocked, a bang-sensitive mutant.	REFM 1 Bellen, Taylor, 2001: 48		
ID|FBrf0144646
TP|abstract
|Drosophila meeting abstract
MABST|Bang-sensitive (bs) mutants exhibit a stereotypic paralysis and seizure
| following exposure to a mechanical shock. In the adult giant fiber
| preparation, seizures and failures that correspond to the defective
| behavior are observed in response to a high frequency buzz (Pavlidis and
| Tanouye, '95 J. Neurosci. 15: 5810). In many respects, these defects are
| similar to the symptoms and physiology of mammalian seizures and epilepsy.
| Anti-epileptic drugs were administered by chronic feeding and injection to
| the bs mutant easily shocked (eas). The mean paralysis and seizure times of
| treated eas flies were examined in comparison to control cultures. Most of
| the drugs administered had no effect on the bs behavior of eas. These
| included carbamazepine, which is thought to decrease excitability through
| sodium channels; ethosuximide, which acts through calcium channels; and
| vigabatrin, an inhibitor of GABA breakdown. Phenytoin (Dilantin), however,
| showed a concentration-dependent decrease in paralysis time. Seizures were
| reduced at high concentrations of this drug but enhanced at intermediate
| dosages. Phenytoin was effective at a concentration of 1-6 mg/ ml when
| included in the food during development or for a chronic feeding of at
| least two weeks. The drug also reduced the time of paralysis at
| concentrations of 0.3-1 mg/ ml when injected into the fly hemolymph.
| Phenytoin is thought to promote sodium influx, which stabilizes the
| threshold against excessive stimulation. Gabapentin, whose mode of action
| is currently not well understood, also showed a concentration-dependent
| decrease in both seizure and paralysis time. The results with this drug,
| however, were less dramatic than with phenytoin. Gabapentin was effective
| at 0.3-3 mg/ ml using a chronic feeding paradigm. The effects of these
| drugs have also been examined physiologically using the giant fiber
| preparation and these results will also be discussed.
AU|Reynolds
|E.R.
AU|Feeney
|L.
AU|Stauffer
|E.
AU|Jacobs
|B.
AU|Kelly
|H.
AU|McKeever
|C.
YR|2001
TI|Human epileptic drugs reduce seizure and paralysis in easily shocked, a bang-sensitive mutant.
JR|Bellen, Taylor, 2001
PG|48
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144647	AU 1 Rheuben et al.	YR 1 2001	TP 1 Abstract	TI 1 Endosomes in vesicle recycling in larval motor nerve terminals.	REFM 1 Bellen, Taylor, 2001: 49		
ID|FBrf0144647
TP|abstract
|Drosophila meeting abstract
MABST|Previous studies using FM1 -43, a fluorescent lipophilic dye that identifies
| endocytotic structures formed in its presence, have furthered understanding
| of synaptic vesicle recycling in several species by allowing visualization
| of populations of organelles in vivo. When this method is used in
| Drosophila, characteristic patterns of dye distribution are seen within the
| terminal, depending upon the method used to evoke endocytosis (Kuromi and
| Kidokoro, 1999). Methods such as high potassium depolarization give rise to
| intense staining of discrete patches in the peripheral parts of the larger
| Type Ib boutons. We examined the composition of these patches at the
| ultrastructural level after photoconverting the FM1 -43 label to an
| electron dense precipitate. They include densely packed synaptic vesicles
| and endosomes, nearly all of which are labeled after K + depolarization.
| The patches involve several presynaptic dens e bodies, and are separated by
| areas of cytoplasm containing only microtubules and occasional
| mitochondria. In the preceding experiments fixation followed a 10 min wash
| period in 0 Ca++ saline, but if the wash period is omitted, a smaller
| fraction of vesic les is labeled, and fewer labeled (and unlabeled)
| endosomes are seen, supporting the hypothesis that significant amounts of
| endocytosis continues after repolarization. When FM1-43 loaded terminals
| are re-stimulated by high K + the fluorescence patches typically disappear,
| indicating that nearly all vesicles and organelles are participating in a
| recycling process. However, if maximal uptake is produced during the
| initial labeling by tetanic stimulation or pre-treatment with cyclosporin
| A, a small amount of fluorescence remains following the second
| depolarization step. Organelles that are labeled under this condition
| include a small number of endosomes and multivesicular bodies, and, rarely,
| fully labeled single vesicles. In addition populations of vesicles with
| small amounts of precipitate in their membranes are sometimes seen. If the
| large molecule horseradish peroxidase is used as a marker for endocytosis,
| a much lower fraction of vesicles is labeled after maximal stimulation, but
| many labeled endosomes are seen. It is possible that endosomes are a
| functional part of a reserve pool, are involved in a recycling process that
| occurs slowly, and are formed at a place on the terminal to which HRP has
| more ready access than to regions in which vesicles are being formed
| directly. Supported by the Genetic Research Fund, College of Veterinary
| Medicine, Michigan State University to MBR, and a grant-in-aid from the
| Ministry of Education, Science, Sports, and Culture to YK.
AU|Rheuben
|M.B.
AU|Yoshihara
|M.
AU|Kuromi
|H.
AU|Kidokoro
|Y.
YR|2001
TI|Endosomes in vesicle recycling in larval motor nerve terminals.
JR|Bellen, Taylor, 2001
PG|49
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144648	AU 1 Rieckhof et al.	YR 1 2001	TP 1 Abstract	TI 1 Analysis of the role of the N-type calcium channel in synapse formation and function.	REFM 1 Bellen, Taylor, 2001: 50		
ID|FBrf0144648
TP|abstract
|Drosophila meeting abstract
MABST|In behavioral screens for temperature-sensitive (TS) paralytic mutations in
| Drosophila that disrupt neuronal signaling, we have identified several TS
| paralytic mutations that disrupt the Drosophila N-type calcium channel
| (Dmca1A). These mutations disrupt synaptic transmission at larval and adult
| (1) neuromuscular junctions (NMJs) and cause a reduction in synapse
| arborization and varicosity number. Morphological defects in varicosity
| number arise after the initial establishment of the synaptic field, as
| embryonic presynaptic terminals appear normal, while third instar
| presynaptic terminals manifest aberrant morphology. In addition, null
| mutations in Dmca1A abolish synchronous evoked vesicle fusion, but do not
| disrupt synapse formation. Together with the absence of presynaptic
| staining with anti-L and anti-T-type calcium channel antibodies, these data
| suggest that the N-type calcium channel is largely responsible for
| presynaptic calcium entry. Our observations also suggest that presynaptic
| calcium entry through N-type calcium channels is not required for initial
| synapse formation, but is an important modulator of synaptic growth. To
| further characterize the role of calcium channels in synapse function, we
| are undertaking a detailed electrophysiological, immunohistochemical, and
| genetic analysis of Dmca1A TS and null mutants. 1. Kawasaki et al., (2000)
| J. Neurosci. 20( 13): 4885-4889
AU|Rieckhof
|G.E.
AU|Yoshihara
|M.
AU|Littleton
|J.T.
YR|2001
TI|Analysis of the role of the N-type calcium channel in synapse formation and function.
JR|Bellen, Taylor, 2001
PG|50
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144649	AU 1 Ritzenthaler and Chiba	YR 1 2001	TP 1 Abstract	TI 1 Myopodia respond to ecotopic synapses.	REFM 1 Bellen, Taylor, 2001: 91		
ID|FBrf0144649
TP|abstract
|Drosophila meeting abstract
MABST|The process of neuromuscular connectivity requires input from both
| presynaptic and postsynaptic cells. We previously reported that during the
| stages of synaptic matchmaking, Drosophila embryonic muscle cells extend
| numerous filopodia-like processes (myopodia) that interact with innervating
| motoneurons. This interaction culminates in t he formation of a "cluster"
| of presumably stabilized myopodia at the innervation site late in
| embryogenesis (hour 16). Clustering behavior was not observed in mutants
| having severe delays in axon outgrowth, although myopodia were present
| initially. This result suggested that myopodia behavior was somewhat
| reliant on the presence of motoneurons. However, whether myopodia behavior
| relied on a general signal from the motoneuron growth cones or was
| influenced by more specific cues from an innervating motoneuron remained
| unclear. We are currently misexpressing various synaptic target recognition
| molecules to induce the formation of ectopic synapses on embryonic muscles
| and are evaluating the behavior of myopodia in such cases. We have found
| that myopodia cluster at the innervation site during the formation of
| ectopic synapses, suggesting that it is the specific interaction between
| synaptic partner cells which drives myopodia behavior. We are also
| investigating myopodia behavior in mutants such as Fasciclin III and
| DN-cadherin in order to evaluate the role of adhesion in motoneuron-muscle
| interaction. These results should provide valuable insight into the
| cell-cell interactions that make neuronal networking possible on a grand scale.
AU|Ritzenthaler
|S.
AU|Chiba
|A.
YR|2001
TI|Myopodia respond to ecotopic synapses.
JR|Bellen, Taylor, 2001
PG|91
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144650	AU 1 Rivlin and Deitcher	YR 1 2001	TP 1 Abstract	TI 1 Analysis of synaptic function and development of adult neuromuscular synapses in the paralytic mutant SNAP-25ts.	REFM 1 Bellen, Taylor, 2001: 51		
ID|FBrf0144650
TP|abstract
|Drosophila meeting abstract
MABST|The best described adult neuromuscular synapses in Drosophila are the
| synapses onto the cervical and coxal muscles (Koenig and Ikeda 1989; Koenig
| et al. 1993). To study synaptic function in the adult, we have developed a
| whole-mount preparation to visualize cervical and coxal synapses with
| confocal microscopy. We are presently using this preparation to examine the
| distribution of synaptic proteins in the adult boutons of the
| temperature-sensitive paralytic mutant, SNAP-25 ts . This study will
| complement an ultrastructural analysis of SNAP-25 ts that revealed an
| increase in the number of morphologically docked vesicles at the permissive
| temperature in the mutant synapse as compared to control synapses. To
| uncover possible mechanisms for this enhancement in vesicle docking, we are
| using an antibody for SNAP-25 and confocal imaging to investigate whether
| the distribution of SNAP-25 has been altered in the mutant synapse. In
| addition, we are using the above preparation to investigate the
| development/ maturation of the cervical and coxal synapses. Because many
| thoracic muscles continue to grow and/ or differentiate after the adult
| emerges from the puparium (Auber 1969; Usherwood 1975), we can monitor the
| effect of muscle growth/ differentiation on the adult synapse.
| Interestingly, we have detected ultrastructural differences in vesicle
| docking in 1-and 4-day old synapses in SNAP-25 ts . While an increase in
| morphologically docked vesicles is observed at the mutant synapse as
| compared to the control in 4-day old adults, no difference in vesicle
| docking was observed in mutant and control synapses in 1-day old adults.
| This suggests that the vesicle docking machinery in SNAP-25 ts differs at
| these two ages. To better understand the basis for these differences, we
| are using pre-and post-synaptic markers to monitor the growth and
| maturation of cervical and coxal synapses after adult emergence in wildtype
| and SNAP-25 ts flies.
AU|Rivlin
|P.K.
AU|Deitcher
|D.L.
YR|2001
TI|Analysis of synaptic function and development of adult neuromuscular synapses in the paralytic mutant SNAP-25ts.
JR|Bellen, Taylor, 2001
PG|51
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144651	AU 1 Barclay et al.	YR 1 2001	TP 1 Abstract	TI 1 Coordinated locomotor pattern generation in larval Drosophila.	REFM 1 Bellen, Taylor, 2001: 52		
ID|FBrf0144651
TP|abstract
|Drosophila meeting abstract
MABST|The larval Drosophila preparation is widely used as a model system for
| investigating neuromuscular physiology in a genetically amenable organism.
| Although larval locomotor behaviour has been extensively investigated, the
| underlying peristaltic locomotor patterns have yet to be described. We
| adapted the standard larval preparation to investigate motor rhythms
| generated by the central nervous system. Dual intracellular recordings were
| made simultaneously from abdominal muscle 6 of segments 3 and 5 on opposite
| sides of the body midline. The recorded rhythmical motor activity had a
| characteristic frequency (0.05 Hz) and was coordinated between the left and
| right sides of the body with appropriate phasing (85%) between serial
| muscle segments, thus constituting a coherent locomotor program. The
| phasing corresponded to anterior to posterior waves of muscular contraction
| as occurs during retrograde peristaltic locomotion. The frequency of the
| locomotor rhythms was found to increase with increasing temperature (Q 10
| =3-5); however, intersegmental phasing was unaffected. Cysteine string
| protein (CSP) is an integral component of the presynaptic exocytotic
| machinery. Larvae with null mutations in the csp gene are characterized by
| temperature -sensitive paralysis and impaired neuromuscular transmission.
| Centrally-generated locomotor rhythms can be used as a convenient assay for
| examining physiology of central synapses. We used the larval motor pattern
| preparation to investigate the effect of the csp null mutation on central
| synapt ic transmission. We found that there was a 50% reduction in the
| ability of csp mutants to generate locomotor rhythms. Locomotor patterns in
| successful mutant preparations had slower, poorly coordinated rhythms with
| altered temperature-sensitivity. We conclude that temperature-sensitive
| paralysis of csp mutants is a result of locomotor circuit failure rather
| than a direct result of synaptic failure of neuromuscular junctions.
AU|Barclay
|J.W.
AU|Atwood
|H.L.
AU|Robertson
|R.M.
YR|2001
TI|Coordinated locomotor pattern generation in larval Drosophila.
JR|Bellen, Taylor, 2001
PG|52
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144652	AU 1 Drummond et al.	YR 1 2001	TP 1 Abstract	TI 1 Dominant negative SNAP24 proteins inhibit synaptic transmission at the neuromuscular junction.	REFM 1 Bellen, Taylor, 2001: 53		
ID|FBrf0144652
TP|abstract
|Drosophila meeting abstract
MABST|Three proteins, syntaxin (Syx), SNAP25 and synaptobrevin (n-Syb), form a
| complex that is thought to be essential in the fusion and recycling of
| synaptic vesicles. The use of mutants and of flies expressing tetanus toxin
| have established the importance of Syx and n-Syb in this process, but to
| date there is no functional information addressing the role of SNAP25 in
| synaptic transmission in flies. A recently discovered homologue of SNAP25,
| SNAP24, has a more widespread distribution than SNAP25, although it too is
| found in the central nervous system. We have adopted a dominant negative
| approach to elucidate the function of SNAP24 and SNAP25 in
| neurotransmission in Drosophila. The dominant negative protein is a
| truncation of SNAP24 which removes the last 20 amino acids, and mimics its
| cleavage by botulinum E toxin (SNAP24 D 186-212). Recombinant forms of both
| SNAP25 and SNAP24 form an SDS-resistant complex with Syx and n-Syb in
| vitro. The complex formed between SNAP25, Syx and n-Syb is
| thermodynamically more stable than that formed with SNAP24. By contrast the
| amount of complex formed by SNAP24 D 186-212, Syx and n-Syb recombinant
| proteins is barely detectable. The in vitro complexes run with a molecular
| weight of about 62kDa whereas complexes isolated from fly heads run at over
| 175kDa suggesting that complexes of wild type proteins are either multimers
| or that they consist of additional proteins. Expression of SNAP24 D 186-212
| in the nervous system results in adult wing and leg phenotypes, with the
| most extreme phenotype being lethality as late embryos. The severity of
| these phenotypes is related to the level of expression of the dominant
| negative protein. Moreover SNAP24 D 186-212 expression inhibits synaptic
| transmission at the larval neuromuscular junction. Overexpression of wild
| type SNAP24 gives none of these phenotypes. Use of dominant negative SNAP24
| suggests that SNAP24 and SNAP25 have a role in synaptic transmission in Drosophila.
AU|Drummond
|J.A.
AU|Neimeyer
|B.
AU|Vilinsky
|I.
AU|Deitcher
|D.
AU|Robinson
|I.M.
YR|2001
TI|Dominant negative SNAP24 proteins inhibit synaptic transmission at the neuromuscular junction.
JR|Bellen, Taylor, 2001
PG|53
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144653	AU 1 Rodan et al.	YR 1 2001	TP 1 Abstract	TI 1 Identification of CNS regions mediating response to ethanol in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 118		
ID|FBrf0144653
TP|abstract
|Drosophila meeting abstract
MABST|Alcohol is widely used for its intoxicating properties, yet its effects on
| the nervous system are only partially understood. Like humans, Drosophila
| melanogaster acutely exposed to ethanol become first activated, then
| uncoordinated, and finally sedated and unarousable. We can quantify some of
| these changes in behavior using an "inebriometer," a glass column with
| obliquely oriented mesh baffles. When exposed to ethanol vapor, flies fall
| through the column as they lose postural control, and the mean elution time
| (MET) of a population of flies can be used as a measure of sensitivity to
| alcohol. Global perturbations in cAMP signaling alter the flies' response
| to alcohol. For example, flies with a mutation in a Ca ++
| -calmodulin-sensitive adenylyl cyclase exhibit increased sensitivity to
| alcohol. We wished to better define the neurons in which this signaling
| pathway is important for the flies' response to ethanol, with the goal of
| identifying some of the components of the neural circuitry underlying these
| behaviors. We are using the GAL4/ UAS system to drive a protein kinase A
| (PKA) -inhibitory transgene in specific regions of the brain and measuring
| the flies' ethanol sensitivity in the inebriometer. We have found that
| expressing the transgene in some brain regions decreases the flies'
| sensitivity to ethanol. Expression in other regions or in muscle has no
| effect, nor does expression of a control transgene. In addition, the
| resistant phenotype is suppressed by co-expression of additional PKA
| catalytic subunit, implying specificity of the transgene. Transgene
| expression does not alter ethanol pharmacokinetics or gross brain
| morphology. The central brain of the fly consists of two main
| substructures: the mushroom bodies (MBs), which are necessary for some
| types of associative learning, and the central complex, which acts as a
| higher order motor control center. We have found that the MBs do not play a
| role in mediating alcohol-induced behavior, whereas expression of the PKA
| transgene in a very small subset of central complex neurons increases MET.
| In addition, our experiments have implicated neurons outside the central
| brain of the fly in which inhibition of PKA alters alcohol sensitivity.
AU|Rodan
|A.R.
AU|Kiger
|J.A.
AU|Heberlein
|U.
YR|2001
TI|Identification of CNS regions mediating response to ethanol in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|118
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144654	AU 1 Rohrbough and Broadie	YR 1 2001	TP 1 Abstract	TI 1 Characterization of central synaptic transmission in identified larval neurons.	REFM 1 Bellen, Taylor, 2001: 54		
ID|FBrf0144654
TP|abstract
|Drosophila meeting abstract
MABST|A current irony for Drosophila neurophysiologists is that despite the large
| body of related genetic, behavioral, and electrophysiological studies,
| examinations of synaptic transmission and activity-dependent plasticity
| have relied almost exclusively on the accessible neuromuscular synapse. Our
| long-term interest in synaptic plasticity and cellular mechanisms of
| learning/ memory depends on developing central neuronal preparations
| amenable to functional synaptic recordings and, ultimately, to detailed
| plasticity studies. The tractability of in vivo central synaptic recordings
| has recently been demonstrated in the embryonic CNS (Baines et al, 1999;
| Baines et al, 2001) . We have recorded functional neuronal and synaptic
| transmission properties in dorsally situated motorneurons in the larval
| ventral nerve cord (VNC), using whole-cell current and voltage clamp
| techniques. Comparison of neuronal GFP markers and intracellular dye
| labeling indicates that these neurons correspond to the identified
| embryonic aCC and RP1-4 motorneurons. Neurons have resting potentials of
| �50 to �60 mV, and fire repetitive action potentials (APs) in response to
| depolarizing current injection. Focal acetylcholine application elicits
| sustained excitatory responses and AP bursts which are reversibly blocked
| by the nicotinic receptor antagonist d-tubocurarine (dtC). GABA application
| elicits hyperpolarizing or weakly depolarizing responses which are
| reversibly blocked by the chloride channel blocker picrotoxin. Multiple
| types of endogenous synaptically-driven activity are observed in most
| recordings. These include frequent fast spontaneous synaptic events (10-50
| pA amplitude, &lt;50 ms duration) resembling unitary epscs, noisier
| sustained "intermediate" currents (20-100 pA, 100-200 ms), and larger
| sustained excitatory "rhythmic" currents (&gt; 100 pA, &gt;200 ms) which
| support bursts of APs. Electrical stimulation of peripheral nerves or the
| VNC neuropil evokes sustained excitatory responses and faster epscs which
| are similar to endogenous synaptic events. Both endogenous forms of
| activity and evoked responses are dependent on external Ca 2+ , reversibly
| blocked by dtC, and reduced at restrictive temperatures in shibire
| conditional synaptic mutants, indicating that cholinergic synaptic
| transmission directly underlies most observed activity. Evoked synaptic
| responses exhibit frequency-dependent plasticity, including short-term
| depression and facilitation. The potential for carrying out in-depth
| functional analysis in this and other neuronal preparations provide a basis
| for future analyses of central transmission and plasticity in Drosophila.
AU|Rohrbough
|J.
AU|Broadie
|K.
YR|2001
TI|Characterization of central synaptic transmission in identified larval neurons.
JR|Bellen, Taylor, 2001
PG|54
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144655	AU 1 Roman et al.	YR 1 2001	TP 1 Abstract	TI 1 P{Switch}: New enhancer detectors that provide both temporal and tissue-specific control of gene expression from UAS transgenes.	REFM 1 Bellen, Taylor, 2001: 76		
ID|FBrf0144655
TP|abstract
|Drosophila meeting abstract
MABST|The ability to control transgene expression in both space and time is
| becoming requisite for further dissection of adult nervous system function
| in Drosophila. We have developed a system with this degree of control that
| utilizes an RU486 inducible form of the Gal4 transcription factor called
| Gene-Switch. The expression of Gene-Switch is controlled through either
| enhancer detectors or with specific promoter/ enhancer constructs.
| Transcriptional activation of UAS transgenes results from Gene-Switch
| binding to the membrane permeable anti-progestin, RU486. Two separate
| enhancer detector constructs have been generated. In the first, the Gene
| -Switch open reading frame is located behind the P-transposase promoter and
| untranslated leader sequence, and in the second Gene -Switch is fused in
| frame to the transposase. These differences were found to affect the
| frequency of patterns detected per line. Both Gene -Switch elements have
| been mobilized to generate many independent lines. Gene-Switch constructs
| have also been made that are driven by the ELAV and MHC promoters, and by
| selected mushroom body enhancers. Together, these lines provide RU486
| inducible expression in many cell and tissue types in larval as well as
| adult stages. The signal to noise ratio of Gene-Switch is exceptional, with
| negligible to undetectable background activation in the absence of RU486.
| The kinetics of reporter induction is rapid and dependent on RU486 dose.
| The uptake of RU486 appears to saturate after 1 hour feeding. Significant b
| -galactosidase expression is induced in as little as three hours after
| feeding, and reaches a plateau around 24 hours. Additionally, the levels of
| RU486 required for Gene-Switch activation appear to have little or no
| effect on the viability, fecundity, or on the general behavior of
| Drosophila. Thus, this system offers experimental control over when and
| where transgenes are expressed, with quick induction and little to no
| background expression or side effects.
AU|Roman
|G.
AU|Osterwalder
|T.P.
AU|Endo
|K.
AU|Zong
|L.
AU|Keshishian
|H.
AU|Davis
|R.L.
YR|2001
TI|P{Switch}: New enhancer detectors that provide both temporal and tissue-specific control of gene expression from UAS transgenes.
JR|Bellen, Taylor, 2001
PG|76
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144656	AU 1 Roman and Davis	YR 1 2001	TP 1 Abstract	TI 1 A screen for innate behavioral defects in mutants of the kurtz non-visual arrestin.	REFM 1 Bellen, Taylor, 2001: 77		
ID|FBrf0144656
TP|abstract
|Drosophila meeting abstract
MABST|Much of the information animals receive from the environment is gathered
| through G protein-coupled receptors (GPCRs). In vertebrates, non-visual
| arrestins bind to and uncouple agonist -bound GPCRs from their interactions
| with heterotrimeric G proteins. These arrestins are also required for the
| internalization, and subsequent recycling of the activated GPCR back to the
| membrane. Thus, non-visual arrestins are necessary for both the
| agonist-dependent desensitization and resensitization of GPCRs. We have
| identified a P element insertion within the only non-visual arrestin in
| Drosophila, which we have named kurtz. These mutants have a broad lethal
| phase that extends from embryogenesis through the larval third instar. The
| induction of a kurtz cDNA with heat shock can rescue homozygotes to
| adulthood, after which further induction of kurtz is not necessary for
| survival. We have examined the expression of kurtz in adults through both
| in situ hybridization and immunohistochemistry. kurtz is expressed widely
| in the nervous system, including both second and third antennal segments,
| and throughout the central brain. This broad expression pattern suggests
| that kurtz may be required in a large number of neural functions. To
| investigate this, we are establishing a behavioral battery that will
| examine motor, sensory, and higher order neural functions. We have begun
| placing rescued homozygous kurtz mutants through this battery. These
| mutants display modest defects in activity within the Trikinetics activity
| monitor. Homozygous kurtz adults show normal sensitivity to benzaldehyde in
| a novel open field paradigm. kurtz mutant females show normal levels of
| sexual receptivity, but mutant males have severe defects in courtship.
| These males have nearly normal courtship latencies, but fail to maintain a
| rigorous level of courtship. This defect is mostly rescued by a heat shock
| induction of the kurtz cDNA three hours prior to the start of the courtship
| assay. These data suggest an acute physiological role for the kurtz
| arrestin in male courtship.
AU|Roman
|G.
AU|Davis
|R.L.
YR|2001
TI|A screen for innate behavioral defects in mutants of the kurtz non-visual arrestin.
JR|Bellen, Taylor, 2001
PG|77
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144657	AU 1 Rothenfluh and Heberlein	YR 1 2001	TP 1 Abstract	TI 1 Behavioral respones to nicotine exposure.	REFM 1 Bellen, Taylor, 2001: 112		
ID|FBrf0144657
TP|abstract
|Drosophila meeting abstract
MABST|Nicotine is a commonly encountered drug of abuse in society. When flies are
| exposed to high doses of volatilized nicotine, they become strongly
| hyperactive and exhibit uncontrollable, seizure-like shaking, followed by
| death. At lower doses, after the initial hyperactivity, exposed flies
| hypolocomote, and after 5-10 minutes they completely recover. We measure
| these behavioral responses in an assay where we test the flies' ability to
| climb, and also measure their self-righting ability. A second assay we use
| is a locomotor tracking system, which utilizes a digital camera and a
| software package (DIAS) to measure locomotion speed and other parameters.
| Nicotine binds to and activates the nicotinic acetylcholine receptor
| (nAChR), of which there are 10 subunits in flies, and no mutant allele is
| available. To learn more about the genetics of nicotine responses, we are
| screening P-element induced mutations generated in our lab to look for
| inserts altering sensitivity to nicotine. Exposing flies to the nAChR
| antagonist mecamylamine results in a behavioral phenotype opposite to the
| one induced by nicotine. Mecamylamine does not hyperactivate flies, but
| induces hypolocomotion, paralysis, and then loss of righting. Aside from
| the acute exposure, we are also investigating the effects of chronic
| nicotine or mecamylamine exposure on the response to nicotine. Preliminary
| studies indicate that feeding flies nicotine induces tolerance and makes
| them less sensitive to the behavioral effects of volatilized nicotine.
| Conversely, mecamylamine-fed flies are more sensitive to the
| hyperactivating effects of nicotine. These results allow for the study of
| neuronal plasticity involved in the behavioral response to nicotine.
AU|Rothenfluh
|A.
AU|Heberlein
|U.
YR|2001
TI|Behavioral respones to nicotine exposure.
JR|Bellen, Taylor, 2001
PG|112
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144658	AU 1 Michard-Vanhee et al.	YR 1 2001	TP 1 Abstract	TI 1 Clock and cycle function differently in lateral neurons differentiation and behavioral rhythms.	REFM 1 Bellen, Taylor, 2001: 113		
ID|FBrf0144658
TP|abstract
|Drosophila meeting abstract
MABST|The brain circadian pacemaker that controls locomotor activity and eclosion
| rhythms is located in a small cluster of cells of the adult brain named
| ventral lateral neurons or LNvs 1 ,2 ,3 . These neurons synthetize a
| pigment-dispersing factor (PDF)-like neuropeptide, the main circadian
| transmitter 2 . PDF appears in small LNvs in the 1 st larval stage and in
| the large LNvs at mid-pupation 4 . We have investigated the role of the
| clock (clk) and cycle (cyc) genes i n the differentiation of the LNvs in
| order to understand how the circadian clock forms in the brain. Besides
| their roles as positive regulators of period (per) and timeless (tim) gene
| expression, clk and cyc control pdf RNA levels in larval and adult small
| LNvs, but not in large LNvs 5 ,6 . In addition, clk jrk and cyc 0 brains
| frequently showed extra and aberrant projections from large LNvs 6 . We
| have recently identified a P-Gal4 enhancer trap (gal1118) that is
| specifically expressed in LNvs 3 , well before PDF expression is
| detectable. We now report that gal1118 expression in the small LNvs is lost
| in clk jrk and very weak in cyc 0 brains, whereas the expression of both
| PDF and gal1118 is developmentally delayed in the large LNvs of the
| mutants. In addition, the presence of CLK in the larval LNs, suggests that
| it acts cell autonomously on pdf and gal1118 transcription. We also show
| that in cyc 0 but not in clk jrk brains, PDF and gal1118 expression in the
| small LNvs can be restored at low temperature, whereas the behavioral
| arrhythmicity of the mutants is not reverted. These results indicate that
| CLK and CYC interact differently for their role in clock neurons
| differentiation and in per and tim transcriptional activation. 1.
| Helfrich-F�rster, C. J Comp Physiol A 182, 435-453 (1998). 2. Renn, S. C.
| et al. Cell 99, 791-802 (1999). 3. Blanchardon, E. et al. Eur J Neurosci
| 13, 871-888 (2001). 4. Helfrich-F�rster, C. J Comp Neurol 380, 335-54
| (1997). 5. Blau, J. and Young, M. W. Cell 99, 661-71 (1999). 6. Park, J. H.
| et al. Proc Natl Acad Sci U S A 97, 3608-3613 (2000).
AU|Michard-Vanhee
|C.
AU|Klarsfeld
|A.
AU|Chelot
|E.
AU|Rouyer
|F.
YR|2001
TI|Clock and cycle function differently in lateral neurons differentiation and behavioral rhythms.
JR|Bellen, Taylor, 2001
PG|113
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144659	AU 1 Ruan and Rao	YR 1 2001	TP 1 Abstract	TI 1 Characterization of genes that interact with Dock/Msn in controlling photoreceptor growth-cone targeting in Drosophila.	REFM 1 Bellen, Taylor, 2001: 234		
ID|FBrf0144659
TP|abstract
|Drosophila meeting abstract
MABST|Establishment of precise photoreceptor-to-optic ganglia connection in the
| adult fly visual system requires the proper control of photoreceptor
| (R-cell) growth -cone motility during development. At third-instar larval
| stage, R8 axons project through the optic stalk into the optic lobe. Within
| optic lobe, R8 axons migrate through the lamina into the medulla layer.
| R1-7 growth cones migrate along the surface of R8 axons into lamina until
| they reach a layer of lamina glial cells. R1-6 growth cones stop migrating
| and terminate within lamina, while R7 growth cones pass through lamina into
| medulla. Previous studies (Garrity et al., 1996, Cell 85: 639-650; Ruan et
| al., 1999, Neuron 24: 595-605) demonstrated that the shutdown of R1-6
| growth-cone motility at lamina requires the SH2/ SH3 adapter protein
| Dreadlocks (Dock) and the Ste20-like Serine/ Threonine kinase Misshapen
| (Msn). We proposed that Dock-linked stop signals activate Msn, which in
| turn phosphorylates some cytoskeletal proteins in decelerating R1-6
| growth-cone motility when they reach the lamina intermediate target. To
| further understand the control of growth-cone motility by the Dock/ Msn
| signaling pathway, we have undertaken a genetic dissection to search for
| genes that interact with Msn. Deficiency lines from the Drosophila stock
| center were analyzed to test if removal of a copy of certain cytological
| region would modify a pre-target growth-cone termination phenotype caused
| by hyper-activation of Msn. From this screen, we identified 22 cytological
| regions containing suppressors and 6 regions containing enhancers. To
| identify corresponding genes, we tested P element insertions and other
| known mutations for potential interactions with msn. Our results
| demonstrated that reducing the dosage of disabled enhanced the Msn
| hyper-activation phenotype. Whereas the phenotype was substantially
| suppressed by reducing the dosage of bifocal (bif), a gene encoding a
| putative actin-binding protein. Phenotypic analysis of bif mutants
| demonstrated that like loss of msn, loss of bif also caused a failure of
| R1-6 growth cones to stop at lamina. Eye-specific expression of bif in bif
| mutants substantially rescued R1-6 targeting defects, suggesting that bif
| is required in R1-6 growth cones for targeting decisions. R-cell
| differentiation and cell fate determination remain normal in bif mutants,
| indicating that R1-6 targeting errors are unlikely due to R1 -6-to-R7/ 8
| fate transformation. Like overexpression of Msn, overexpression of Bif also
| caused pre-target growth cone termination. Biochemical analysis is underway
| to determine if Msn directly phosphorylates Bif protein in inducing the
| rearrangements of growth-cone cytoskeleton leading to the shutdown of
| growth-cone motility.
AU|Ruan
|W.
AU|Rao
|Y.
YR|2001
TI|Characterization of genes that interact with Dock/Msn in controlling photoreceptor growth-cone targeting in Drosophila.
JR|Bellen, Taylor, 2001
PG|234
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144660	AU 1 Saitoe and Tamura	YR 1 2001	TP 1 Abstract	TI 1 Impairment of olfactory memory during aging in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 114		
ID|FBrf0144660
TP|abstract
|Drosophila meeting abstract
MABST|Most of the animals show memory decay during aging. However, little is known
| about molecular mechanism of age-related memory decay. A major obstacle in
| understanding the molecular mechanism of age-dependent memory decay has
| been the life span of animal models. Fruit fly, Drosophila, has a very
| short life span (50 to 60 days on average), and the powerful genetic and
| molecular techniques are applicable to explore the molecular mechanism.
| However, age-dependent memory decay in this organism has not been well
| analyzed. By single Pavlovian olfactory conditioning, four distinct
| temporal phases sequentially appear: learning (LRN), short-term memory
| (STM), middle-term memory (MTM) and anesthesia-resistant memory (ARM). In
| this study, we have examined the decay of memory formation during aging in
| Drosophila by using Pavlovian olfactory conditioning procedure. We found
| two temporally distinct steps in memory decay: modest impairment in LRN in
| 10-day-old, and significant impairment of MTM formation in 15-day-old adult
| flies. Although modest impairment in LRN did not increase further, the
| ability to form middle-term memory decay further as age forward. Moreover,
| another memory phases, STM and ARM, were unaffected as long as 50-day-old.
| These results suggest that not overall memory phases, but specific LRN and
| MTM become to be disrupted during aging.
AU|Saitoe
|M.
AU|Tamura
|T.
YR|2001
TI|Impairment of olfactory memory during aging in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|114
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144661	AU 1 Sanchez-Soriano et al.	YR 1 2001	TP 1 Abstract	TI 1 The influence of targeted changes of synaptic transmission properties on the development of identified neurons in Drosophila.	REFM 1 Bellen, Taylor, 2001: 55		
ID|FBrf0144661
TP|abstract
|Drosophila meeting abstract
MABST|During nervous system development, neurons have to grow into their target
| areas and form synaptic contacts with appropriate cells. This determines
| the circuits in which information can flow. Furthermore, the appropriate
| types of synapses (e. g. using appropriate transmitters and receptors) have
| to be established in a co-ordinated manner between the connected cells.
| This is a prerequisite for correct regulation of transmission and
| information flow within the neuronal circuits. We are interested in
| mechanisms underlying the embryonic develoment of synapses. In this project
| we want to find out whether choice of transmitter and partner cells are
| regulated interdependently. To this end we manipulate the type of
| transmitter of identified cells and analyse potential effects on growth and
| partner choice. To manipulate transmission, we use the Gal4/ Uas-system and
| express gene products required for GABAergic transmission ectopically in
| non-GABAergic cells. The proteins we express are the GABA synthesase GAD,
| the vesicular GABA transporter and the GABA receptor Rdl. So far our
| analyses show that production of the inhibitory transmitter GABA can be
| induced ectopically in non-GABAergic cells via targeted expression of GAD.
| Changes in amount and distribtion of GABA upon expression of the vesicular
| GABA transporter suggest that the transporter is functional. Also the GABA
| receptor seems to function since its expression in the nervous system, but
| not in the musculature, leads to late embryonic lethality. We have now
| started to analyse effects of the expression of these proteins on
| morphological properties of the targeted cells. This work is supported by
| the Volkswagen-Foundation (I/ 75 471)
AU|Sanchez-Soriano
|N.
AU|Technau
|G.M.
AU|Prokop
|A.
YR|2001
TI|The influence of targeted changes of synaptic transmission properties on the development of identified neurons in Drosophila.
JR|Bellen, Taylor, 2001
PG|55
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144662	AU 1 Sandstrom and Nash	YR 1 2001	TP 1 Abstract	TI 1 Effects of volatile general anesthetics on the physiology of the larval neuromuscular junction.	REFM 1 Bellen, Taylor, 2001: 56		
ID|FBrf0144662
TP|abstract
|Drosophila meeting abstract
MABST|Although volatile general anesthetics have been shown to perturb many
| neurophysiological functions, the link between these effects and behavioral
| anesthesia remains unclear. We are using Drosophila as a model system to
| investigate the mode of action of these agents, and previous studies have
| isolated mutants that perturb the anesthetic responses of adult flies. To
| provide more tools to elucidate the connection between genes, neurons and
| behavior, it was desirable to be able to measure the effects of volatile
| anesthetics on excitability and synaptic transmission. To this end, we have
| developed a preparation for application of volatile anesthetics onto the
| larval neuromuscular junction. A variety of ether derivatives that
| anesthetize mammals and adults flies also immobilize Drosophila larvae; the
| dose of each agent required for larval immobility is similar to that which
| anesthetizes the other animals. In contrast to the immobilization produced
| by ether derivatives, halothane and chloroform produce strong muscle
| contractions, resulting in whole-body shortening that reverses when the
| agents are removed. At the neuromuscular junction, the ether derivative
| isoflurane produces several effects at physiologically-relevant
| concentrations. Motoneuron spike threshold increases markedly, implying an
| effect on the balance between Na + and K + channel function in the axon. At
| the synapse on muscle 6, mEJC frequency increases, while EJC amplitude
| decreases modestly. The latter observations suggest that isoflurane
| modulates synaptic vesicle release, eit her directly or, for example, via
| an effect on Ca 2+ metabolism. Based on mEJC size, isoflurane has no
| measurable effect on glutamate receptor sensitivity. Work is ongoing to
| assess the effects of anesthetics on short -term synaptic plasticity, and
| to determine the physiological effects of mutations that affect anesthetic
| sensitivity in behavioral assays.
AU|Sandstrom
|D.J.
AU|Nash
|H.A.
YR|2001
TI|Effects of volatile general anesthetics on the physiology of the larval neuromuscular junction.
JR|Bellen, Taylor, 2001
PG|56
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144663	AU 1 Santschi et al.	YR 1 2001	TP 1 Abstract	TI 1 Characterization of Derailed2 in the developing Drosophila CNS.	REFM 1 Bellen, Taylor, 2001: 235		
ID|FBrf0144663
TP|abstract
|Drosophila meeting abstract
MABST|Axon guidance mechanisms include both long-and short-range attractant and
| repellent cues. We have identified Derailed2 (Drl2), a novel member of the
| Drosophila Ryk family of receptor tyrosine kinases. Drl2 bears strong
| sequence homology to Drl, a cell-surface receptor known to play a critical
| role in guiding commissural axonal trajectories across the midline through
| the anterior (versus the posterior) commissure. In situ hybridization
| analysis has revealed that Drl2 is expressed in the CNS and appears to be
| restricted to a subset of neurons distinct from those expressing Drl. To
| determine the identity of these neurons, we fused drl2 regulatory sequences
| to axon-targeted tau-based reporters. These promoter fusions reveal
| expression in specific classes of motorneurons. We are currently using Drl2
| antibodies to confirm these observations and to determine the precise
| distribution of the Drl2 protein. Work in progress includes an assessment
| of Drl2 ligand distribution using an in vivo binding assay, and imprecise
| excision of a P element inserted near the drl2 locus (see McKinnon et al.,
| this meeting) to generate drl2 loss-of-function mutations.
AU|Santschi
|L.
AU|Yoshikawa
|S.
AU|McKinnon
|R.D.
AU|Thomas
|J.B.
YR|2001
TI|Characterization of Derailed2 in the developing Drosophila CNS.
JR|Bellen, Taylor, 2001
PG|235
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144664	AU 1 Satoh et al.	YR 1 2001	TP 1 Abstract	TI 1 A dominant negative Rab small GTPase, (Rab11N124I) selectively affects rhodopsin traffic in fly photoreceptors.	REFM 1 Bellen, Taylor, 2001: 139		
ID|FBrf0144664
TP|abstract
|Drosophila meeting abstract
MABST|Well-organized vesicle transport systems are essential for cell
| morphogenesis. Developing Drosophila photoreceptors provide a useful model
| to investigate the mechanisms of vesicle traffic that make and maintain
| complex cell structures. We first used indirect fluorescence
| immunohistochemistry to characterize the developmental expression of
| several integral membrane proteins, including the photosensory protein,
| rhodopsin, TRP, a sensory membrane ion channel, and the Na + -K + -ATPase
| in developing photoreceptors. Rhodopsin expression begins at about 70% of
| pupal development. Prior to its delivery to the photosensitive organelle,
| the rhabdomere, a specialization of the apical plasma membrane, rhodopsin
| is concentrated in globular structures we term "Rhodopsin-containing Large
| Vesicles (RLVs)". Interestingly, each RLV associates with one or more actin
| patches. Most of the RLVs appear tethered via actin patches to the retinal
| terminal web (RTW), a specialization of the cortical actin cytoskeleton.
| RLVs contain another rhabdomere protein, TRP, but not the basolateral Na +
| -K + -ATPase . These observations suggest that RLVs are organelles involved
| in post -Golgi traffic to the rhabdomere. Next, we identified RLVs of pupal
| retina using immnoelectron microscopy, and surprisingly found that they are
| multi vesiclur bodies (MVB). This suggests that newly synthesized Rhodopsin
| is delivered to endocytic compartment before they reach the final
| destination, the rhabdomere. Rab proteins are small GTPases implicated in
| membrane traffic specificity. Rab11 immunolocalizes to the base of the
| developing rhabdomere in small punctuate structures in addition to the
| trans side of Golgi. In order to investigate Rab11's role, we expressed a
| dominant negative Rab11, Rab11N124I, and observed its effect on membrane
| delivery. Transport of rhodopsin and TRP to the rhabdomere is completely
| inhibited and numerous unusual vesicles bearing Rhodopsin or TRP accumulate
| in photoreceptor. However, there is no effect on Na + -K + -ATPase
| transport. These results suggest that Rab11 is involved in the formation of
| RLVs and the selective delivery to the rhabdomere.
AU|Satoh
|A.
AU|Ozaki
|K.
AU|Kawamura
|S.
AU|Ready
|D.
YR|2001
TI|A dominant negative Rab small GTPase, (Rab11N124I) selectively affects rhodopsin traffic in fly photoreceptors.
JR|Bellen, Taylor, 2001
PG|139
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144665	AU 1 Schulte and Auld	YR 1 2001	TP 1 Abstract	TI 1 Gliotactin directs the formation of septate junctions to establish the blood-nerve barrier.	REFM 1 Bellen, Taylor, 2001: 158		
ID|FBrf0144665
TP|abstract
|Drosophila meeting abstract
MABST|Gliotactin is a cholinesterase-like molecule that is necessary for the
| ensheathment of peripheral nerves by glia during embryonic nervous system
| development. Gliotactin mutants die as embryos because of paralysis
| resulting from a breakdown of the glial based Blood-Nerve-Barrier (BNB).
| Glial septate junctions found between apposing glial-glial membranes
| constitute the seal of the BNB. Septate Junctions (SJs) are analogous to
| vertebrate tight junctions and function in part as permeability barriers.
| It is unknown if Gliotactin is a component of these junctions, or if SJs
| are necessary to facilitate axon ensheathment by glia. However, it is
| possible that the ensheathment defect seen in gliotactin mutants is
| secondary to deficient SJ development. In addition to being expressed in
| glia, Gliotactin is also expressed in other tissues which have SJs, such as
| the epidermis. The molecular constituents of SJs in the Drosophila
| epidermis have been intensively characterized in previous studies. To gain
| a better understanding of the subcellular localization of Gliotactin, and
| to further explore gliotactin mutant phenotypes, we analyzed septate
| junction development in the epidermis of gliotactin mutants. We show that
| in the absence Gliotactin, various SJ markers are mislocalized, indicating
| that Gliotactin is necessary for SJ formation in the epidermis. The loss of
| the BNB integrity in gliotactin mutants is similarily likely to be a direct
| consequence of a loss of glial SJs. In gliotactin mutants, the localization
| of apical epidermal cellular markers is not affected. This indicates that
| the cellular polarity of the epithelia is maintained despite a loss of SJs.
| Interestingly, ectopic expression of Gliotactin, in the epidermis using the
| GAL4 system, results in a re-distribution of SJ markers around the surface
| of the cell. In these studies, Gliotactin appears to be able to direct the
| formation of ectopic SJs to the sites of its localization. Interestingly,
| ectopic expression of Gliotactin in the peripheral nervous system (PNS)
| glia, during their migrational phases, results in glial stalls. Gliotactin
| is normally expressed in the PNS glia at the end of their migration phase
| and just prior to SJ development. This result suggests that abnormal early
| expression of Gliotactin, in the PNS glia, causes the premature formation
| of SJs which in turn blocks glial migration.
AU|Schulte
|J.
AU|Auld
|V.J.
YR|2001
TI|Gliotactin directs the formation of septate junctions to establish the blood-nerve barrier.
JR|Bellen, Taylor, 2001
PG|158
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144667	AU 1 Sigrist et al.	YR 1 2001	TP 1 Abstract	TI 1 The postsynaptic glutamate receptor subunit DGluR-IIA mediates long-term plasticity in Drosophila.	REFM 1 Bellen, Taylor, 2001: 246		
ID|FBrf0144667
TP|abstract
|Drosophila meeting abstract
MABST|The larval neuromuscular junction (NMJ) of Drosophila undergoes
| activity-dependent morphological and functional changes throughout its
| development to ensure efficient depolarization of muscle fibers. We have
| recently shown that these alterations are largely controlled by
| subsynaptically localized translation, which in addition results in an
| elevated expression of the postsynaptic glutamate receptor subunit
| DGluR-IIA (1). We therefore assessed the role of regulated glutamate
| receptor expression for the development and plasticity of larval NMJs. Here
| we show that the transgenic overexpression of DGluR-IIA alone results in an
| increased recruitment of active zones, strengthened signal transmission and
| a corresponding size increase of NMJs. Ultrastructural evidence suggests
| that this additional junctional growth may be the result of a homeostatic
| regulation of the density of active zones within NMJs. Reduced or
| eliminated DGluR-IIA expression suppressed the additional junctional
| outgrowth seen in animals with increased neuronal activity and elevated
| subsynaptic translation. Complementary results were obtained from similar
| treatments using the subunit DGluR-IIB. These data show that the subunit
| composition of postsynaptic glutamte receptors is critical for the
| establishment of long-lasting functional and structural changes at
| Drosophila NMJs. (1) Sigrist et al., Nature 405, 1062-1065.
AU|Sigrist
|S.J.
AU|Thiel
|P.R.
AU|Reiff
|D.F.
AU|Schuster
|C.M.
YR|2001
TI|The postsynaptic glutamate receptor subunit DGluR-IIA mediates long-term plasticity in Drosophila.
JR|Bellen, Taylor, 2001
PG|246
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144666	AU 1 Reiff and Schuster	YR 1 2001	TP 1 Abstract	TI 1 The role of morphological alterations in long-term strengthened signal transmission.	REFM 1 Bellen, Taylor, 2001: 57		
ID|FBrf0144666
TP|abstract
|Drosophila meeting abstract
MABST|Accumulating evidence suggests that long-term synaptic plasticity is
| associated with structural rearrangements within the neuronal circuitry. At
| developing neuromuscular junctions of Drosophila increased neuronal
| activity and elevated postsynaptic translation result in an enhancement of
| junctional transmission and a correlated growth of additional synaptic
| boutons (1). Here we analyzed the role of these morphological changes for
| junctional signal transmission by genetically interfering with long-term
| plasticity at developing NMJs of Drosophila larvae. Using the Ca-sensitive
| protein yellow cameleon-2 we analyzed in these animals the interplay
| between presynaptic Ca-dynamics, postsynaptic responses and locomotor
| behavior. We show that long-term strengthening of signal transmission did
| not alter presynaptic Ca-dynamics, mEJCs or muscle input resistances,
| indicating that long-term plasticity is largely mediated by junctional
| growth and an elevated number of normally operating release sites. This
| ensures increased junctional currents and strengthened locomotor
| performance. In contrast, mutants with restricted junctional growth show
| upregulated presynaptic Ca-influx accompanied by strong synaptic depression
| and significant locomotor defects. These data suggest that the addition of
| boutons is required to maintain the density of active release site and
| thereby to ensure homeostasis of basal synaptic parameters. Therefore
| morphological changes at larval NMJs consolidate enhanced signal
| transmission. (1) Sigrist et al., Nature 405, 1062-1065.
AU|Reiff
|D.F.
AU|Schuster
|C.M.
YR|2001
TI|The role of morphological alterations in long-term strengthened signal transmission.
JR|Bellen, Taylor, 2001
PG|57
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144668	AU 1 Stowers et al.	YR 1 2001	TP 1 Abstract	TI 1 Transport of mitochondria to synapses requires Milton, a new kinesin associated protein.	REFM 1 Bellen, Taylor, 2001: 245		
ID|FBrf0144668
TP|abstract
|Drosophila meeting abstract
MABST|A prerequisite for synaptic transmission is intracellular transport of
| organelles to synaptic terminals. Intracellular transport, in turn, is
| thought to require adapter proteins for molecular motors in order to
| identify and bind specific cargoes, determine destinations, and anchor
| cargoes after transport. We have cloned and characterized a protein,
| Milton, that appears to serve as an adapter protein between kinesin and
| mitochondria. Milton was identified as a genetic locus which, when made
| homozygous in the photoreceptors of the fly, prevented normal phototactic
| behavior and removed the on/ off transients of the ERG, despite normal
| phototransduction. Mitochondria are completely absent from the milton
| photoreceptor nerve terminal and axon, but present and apparently
| functional in the cell body. Photoreceptor synapses are ultrastructurally
| normal in all other respects. Sucrose gradient fractionation experiments
| demonstrated an association between Milton and mitochondria while
| coimmunoprecipitation experiments and mass spectrometry revealed an
| association between Milton and kinesin heavy chain (KHC). Milton protein is
| expressed in axonal and synaptic regions of the fly's brain. milton
| transcripts were detected at all stages of development and null mutants die
| as second-instar larvae, suggesting a widespread role. Milton shares highly
| conserved regions with two human homologs of unknown function. Milton also
| contains a domain with lesser but significant homology to the
| Huntingtin-binding domain of Huntingtin-associated protein 1 (HAP1). We
| propose that Milton is a mitochondrion-specific kinesin adapter protein
| required for axonal transport of mitochondria.
AU|Stowers
|R.S.
AU|Megeath
|L.J.
AU|Andrzejak
|J.G.
AU|Meinertzhagen
|I.A.
AU|Schwarz
|T.L.
YR|2001
TI|Transport of mitochondria to synapses requires Milton, a new kinesin associated protein.
JR|Bellen, Taylor, 2001
PG|245
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144669	AU 1 Scott and Axel	YR 1 2001	TP 1 Abstract	TI 1 Characterization of Drosophila gustatory receptors.	REFM 1 Bellen, Taylor, 2001: 8		
ID|FBrf0144669
TP|abstract
|Drosophila meeting abstract
MABST|A novel family of approximately 60 candidate gustatory receptors (GRs) was
| recently identified by searching the Drosophila genome database for
| predicted seven transmembrane domain proteins 1 . We have characterized the
| expression patterns of members of this family and find that GR genes are
| likely to encode both gustatory and olfactory receptors in adult flies and
| larvae 2 . In situ hybridization and transgene experiments reveal that each
| GR is expressed in a small subset of chemosensory neurons and that
| different GRs are expressed in non-overlapping subsets. The diversity of
| receptors and their segregation into different neurons in the periphery
| suggests that flies may be able to recognize a large number of chemical
| cues. We are interested in how gustatory information in the periphery is
| represented in the brain and the identification of receptors provides the
| opportunity to examine projections of functionally distinct gustatory
| neurons. We have followed the axon termini of neurons bearing the same GR
| into the initial gustatory center of the adult brain, the subesophageal
| ganglion (SOG), and find a diffuse web of convergence. Single cell mosaic
| analyses reveal that the projection pattern of a single neuron
| recapitulates the pattern of the whole. However, neurons with the same
| receptor residing in different tissues in the periphery project to distinct
| regions of the SOG. To map different gustatory inputs, we have generated
| transgenic flies using two amplifiable systems to differentially label axon
| termini from neurons with different GRs. Finally, we are attempting to
| identify ligands for GRs to determine the functional significance of
| different projection patterns. The long term goal of these studies is to
| understand the neural circuitry underlying gustatory behaviors in the fly.
| References: 1 Clyne, P. J., Warr, C. G. and Carlson, J. R. (2000).
| Candidate Taste Receptors in Drosophila. Science 287, 1830-1834. 2 Scott K,
| Brady R Jr, Cravchik A, Morozov P, Rzhetsky A, Zuker C, and Axel R. (2001)
| A chemosensory gene family encoding candidate gustatory and olfactory
| receptors in Drosophila. Cell. 104, 661-73.
AU|Scott
|K.
AU|Axel
|R.
YR|2001
TI|Characterization of Drosophila gustatory receptors.
JR|Bellen, Taylor, 2001
PG|8
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144670	AU 1 Sedaghat and Sonnenfeld	YR 1 2001	TP 1 Abstract	TI 1 Molecular genetic analysis of jing, a C2H2 zinc finger transcription factor, during central nervous system development.	REFM 1 Bellen, Taylor, 2001: 159		
ID|FBrf0144670
TP|abstract
|Drosophila meeting abstract
MABST|The establishment of the central nervous system in Drosophila melanogaster
| has been investigated for many years. Recent studies have shown that the
| specification of glia and neuronal identities is controlled by the
| combinatorial expression of transcription factors. Some members of the
| bHLH-PAS family like single-minded( sim) and tango( tgo) regulate glial and
| neuronal differentiation in numerous organisms. We have studied the role of
| the jing gene in embryonic CNS development. The embryonic expression
| pattern of jing will be presented. We show the presence of jing in glial
| and neuronal precursors and differentiated cells. EMS-induced jing
| mutations have been created and a phenotypic analysis performed. Using
| CNS-specific antibodies these studies establish a role for jing in the
| differentiation of CNS neurons and glia. The development of the Drosophila
| embryo is a process that integrates cell proliferation and differentiation
| with programmed cell death. We show jing mutations induce apoptosis in CNS
| glia and neurons. We therefore propose that jing function is required for
| the survival and differentiation of these cells during embryonic development.
AU|Sedaghat
|Y.
AU|Sonnenfeld
|M.
YR|2001
TI|Molecular genetic analysis of jing, a C2H2 zinc finger transcription factor, during central nervous system development.
JR|Bellen, Taylor, 2001
PG|159
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144671	AU 1 Seeger et al.	YR 1 2001	TP 1 Abstract	TI 1 Mechanisms of Commissureless function in regulating axon guidance at the CNS midline.	REFM 1 Bellen, Taylor, 2001: 86		
ID|FBrf0144671
TP|abstract
|Drosophila meeting abstract
MABST|Two key regulators of axon guidance at the Drosophila CNS midline are
| Commissureless (Comm) and Roundabout (Robo). Robo is the receptor for the
| repulsive guidance cue Slit, and activation of Robo by Slit prevents
| Robo-expressing axons from crossing the CNS midline. Comm is required for
| axons to cross the CNS midline boundary; it encodes a novel transmembrane
| protein, and is thought to function by regulating the cell surface
| accumulation of the Robo receptor. We have been addressing how Comm and
| Comm-related proteins regulate the Drosophila family of Robo receptors. We
| find that Comm and Robo form a complex that leads to the clearance of Robo
| from the cell surface, a process facilitated by a specific region of the
| Comm cytoplasmic domain. Comm and Robo can be co-immunoprecipitated from
| embryo extracts, indicating that these proteins interact directly or as
| part of a larger complex. In addition, confocal microscopy demonstrates
| that Comm and Robo colocalize in punctuate vesicles during various stages
| of embryonic CNS development. We have analyzed the clearance of Robo by
| Comm in some detail by co-expressing both Comm and Robo in Drosophila
| Schneider 2 cells. We have identified a 50 amino acid region of the Comm
| cytoplasmic domain that is critical for Robo clearance. This region of Comm
| encodes 5 tyrosine residues that are highly conserved in Comm homologues
| from D. hydei and D. virilis. Systematic mutational analysis of these
| tyrosines indicates that none are absolutely required. Only when pairs of
| tyrosine residues are mutated is partial or complete loss of Comm-mediated
| Robo clearance observed. Correspondingly, we have found that the
| transmembrane domain and the first 60 amino acids of the cytoplasmic domain
| of Robo is sufficient for Comm-mediated clearance. The essential
| requirement for lysine residues in this region is consistent with a
| ubiquitin-dependent mechanism for Robo clearance. Furthermore, Comm-related
| proteins, Comm2 and Comm3, are also capable of clearing Robo from the cell
| surface (to varying degrees). Also, Comm family members can regulate the
| various Drosophila Robo family members, and Comm family members can
| interact with each other as indicated by co-immunoprecipitation assays.
| Finally, we have been addressing where Comm functions within the embryonic
| CNS. We have not been able to find data that supports the "transfer
| hypothesis" as described previously (Neuron 16: 501). Instead, various
| lines of experimentation suggest a cell autonomous, neuronal requirment for
| Comm. Our current models of Comm function at the CNS midline boundary and
| during synaptogenesis will be presented.
AU|Seeger
|M.A.
AU|Choi
|Y.J.
AU|McGovern
|V.
AU|Pinsonneault
|J.
YR|2001
TI|Mechanisms of Commissureless function in regulating axon guidance at the CNS midline.
JR|Bellen, Taylor, 2001
PG|86
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144672	AU 1 Sepp and Auld	YR 1 2001	TP 1 Abstract	TI 1 Visualization of actin in glia: Glial migration and ensheathement of axons is coordinated by Rho and GTPases.	REFM 1 Bellen, Taylor, 2001: 160		
ID|FBrf0144672
TP|abstract
|Drosophila meeting abstract
MABST|Rho GTPases act as molecular switches that help regulate the dynamic actin
| cytoskeletal rearrangements involved in cell migration. Rho GTPases are
| expressed in both vertebrate and invertebrate glia. Their roles in glial
| cell migration are not well understood since no studies have specifically
| addressed their function in vivo. We are pursuing an analysis of actin
| dynamics to determine which GTPases affect the migration of glial cells
| into the embryonic PNS. We are targeting the ectopic expression of dominant
| negative, constitutively activated, and wild type forms of Rho GTPases
| specifically to glial cells during their normal migrational phases using
| the GAL4 system. The resultant effects on actin cytoskeletal rearrangements
| are being assessed using fluorescence imaging of actin-GFP which is also
| expressed specifically in the glial cells. Mutant variants of Rho1 and Rac1
| cause specific effects on actin structure. As well, alteration of Rho1 and
| Rac1 activity in peripheral glia prevents their normal dynamic
| morphological changes from occurring. Accordingly, the glia are unable to
| guide the formation of peripheral nerves, resulting in peripheral nerve
| patterning defects and failure to properly ensheathe axon tracts. Embryos
| expressing mutant variants of Rho1 and Rac1 in peripheral glia do not
| survive to larval stages. In contrast, ectopic glial expression of cdc42
| GTPase variants do not visibly alter glial migration and wrapping. Embryos
| expressing constitutively activated cdc42 can reach larval stages, although
| their movement is uncoordinated. Together, the data reveal the structure of
| the peripheral glial actin cytoskeleton and show that Rac1 and Rho1 but not
| cdc42 can dynamically alter actin arrangements in the glia during development.
AU|Sepp
|K.J.
AU|Auld
|V.J.
YR|2001
TI|Visualization of actin in glia: Glial migration and ensheathement of axons is coordinated by Rho and GTPases.
JR|Bellen, Taylor, 2001
PG|160
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144673	AU 1 Sharma and Eberl	YR 1 2001	TP 1 Abstract	TI 1 Characterization of the Drosophila cytoplasmic dynein heavy chain 1B and its potential role in hearing.	REFM 1 Bellen, Taylor, 2001: 140		
ID|FBrf0144673
TP|abstract
|Drosophila meeting abstract
MABST|Chordotonal organs function as vi bration sensors in the antenna to mediate
| hearing. The beethoven gene (btv) was identified in an EMS mutagenesis
| screen for mutations that disrupt a behavioral auditory response to
| courtship song. The phenotypes associated with this mutation indicate that
| btv plays a role in chordotonal organ function. Homozygous btv flies
| exhibit a drastic reduction in the sound-evoked compound action potentials
| in the antennal nerve. Electron microscopy studies reveal morphological
| disruptions of the chordotonal neurons, notably in the dendritic cilia. The
| minimal btv genetic interval in 36D contains a male sterile locus in
| addition to btv, as revealed by overlapping chromosomal deletions. Both btv
| alleles are male fertile, so the male sterile locus is likely a separate
| gene. One of the two major predicted genes in this region is homologous to
| the 1b class of cytoplasmic dynein heavy chains (DHC1b), the other being a
| cadherin. In C. elegans, DHC1b is required for intraflagellar transport and
| integrity of the sensory cilia, while rat DHC1b was identified in testes
| and may be important for intraflagellar transport in sperm tails. Thus the
| DHC1b is an excellent candidate for either btv or the male sterile locus.
| Furthermore it may be essential for hearing even if it is not encoded by
| btv. To address these questions, we are currently utilizing an RNA
| interference approach to disrupt DHC1b function, as well as expression
| studies to determine the spatial and temporal expression patterns.
AU|Sharma
|Y.
AU|Eberl
|D.F.
YR|2001
TI|Characterization of the Drosophila cytoplasmic dynein heavy chain 1B and its potential role in hearing.
JR|Bellen, Taylor, 2001
PG|140
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144674	AU 1 Shaw	YR 1 2001	TP 1 Abstract	TI 1 Homeostatic and circadian aspects of sleep-like behavior in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 172		
ID|FBrf0144674
TP|abstract
|Drosophila meeting abstract
MABST|Sleep is a ubiquitous phenomenon that has been found in all mammals, birds
| and reptiles that have been properly studied. Despite its prevalence
| throughout the animal kingdom and our daily lives, decades of sleep
| research, mostly on mammals, have not been able to solve the mystery of why
| we need to sleep. Nonetheless, there is little doubt that vertebrates need
| to sleep and that sleep serves a vital biological function. The most
| compelling evidence of this need can be found from chronic total sleep
| deprivation studies in rats. When rats are prevented from sleeping they die
| in 17 days, about as long as it takes to die from food deprivation.
| Although it was hoped that these studies would reveal the function of
| sleep, the cause of death in sleep deprived animals remains unknown. Using
| behavioral, ontogenetic pharmacological, molecular, and genetic
| investigations I have recently shown that Drosophila rest shares many
| critical features with mammalian sleep. To extend these studies 74 lines
| containing mutations of genes expressed in the CNS were evaluated along
| with 2,400 autosomal P-element insertion lines obtained from t he Berkeley
| Drosophila Genome Project. Sleep wake cycles were thoroughly evaluated
| using established protocols developed in my laboratory. Twenty mutant lines
| (0.81%) exhibited daily sleep quotas that deviated from the mean of all
| mutant lines by more than two standard deviations. These lines were
| subjected to total sleep deprivation by gentle handling in order to
| evaluate the integrity of sleep homeostasis. Homeostatic regulation was
| dramatically altered in line #14. Upon release from 1, 3, and 6 hours of
| sleep deprivation, these flies recovered three times the amount of sleep
| that was lost (vs. 40% in wild-type flies). Furthermore, these flies began
| to die when the deprivation was extended past 10 hours suggesting that the
| increase in recovery sleep after shorter deprivations reflected an
| acceleration of the deleterious effects of waking rather than an impairment
| of the recovery process. Preliminary data indicate that this mutant is not
| merely hyper-responsive to stresses but to prolonged wakefulness per se.
AU|Shaw
|P.
YR|2001
TI|Homeostatic and circadian aspects of sleep-like behavior in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|172
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144675	AU 1 Williams and Shephard	YR 1 2001	TP 1 Abstract	TI 1 Persistent larval neurons guide the growth of adult sensory axons in Drosophila.	REFM 1 Bellen, Taylor, 2001: 169		
ID|FBrf0144675
TP|abstract
|Drosophila meeting abstract
MABST|Our recent work has shown that in Drosophila many larval sensory neurons
| persist through metamorphosis and retain their central arborisations
| intact. Furthermore the axon pathways defined by the persistent neurons
| prefigure pathways taken by ingrowing adult sensory axons. This observation
| led to the hypothesis that the persistent axons pioneer the adult pathways
| and guide the growth of adult sensory axons within the CNS. To test this
| hypothesis we used laser ablation to kill identified larval neurons and
| assayed the effects on the growth of adult axons. The work shows that
| selective ablation, during larval life, of the dorsal and lateral groups of
| sensory neurons in the mesothorax caused severe defects in the central
| afferent projections from sensory neurons on the adult wing and notum. The
| defects: axon spiralling in the peripheral nerve, meandering axons and
| ectopic axonal projections are indicative of failure in axon growth and
| guidance. The data show that persistent neurons provide essential guidance
| cues for axon growth at several stages in adult sensory axon development.
| Persistent neurons are required for peripheral pathfinding, entry into the
| CNS and growth within the CNS. The ablation of subsets of the persistent
| neurons reveals that the axons of different persistent neurons serve
| specific guidance roles within the CNS. Thus neurons in the dorsal cluster
| are required for guidance of adult neurons to and across the midline
| whereas neurons in the lateral cluster are required to guide the
| posteriorly directed growth. The experiments show that larval sensory
| neurons play an important 'pioneering' role in the assembly of ordered
| sensory arrays in the adult CNS and are responsible for selective pathway choice.
AU|Williams
|D.W.
AU|Shephard
|D.
YR|2001
TI|Persistent larval neurons guide the growth of adult sensory axons in Drosophila.
JR|Bellen, Taylor, 2001
PG|169
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144676	AU 1 Siechen and Chiba	YR 1 2001	TP 1 Abstract	TI 1 Axonal growth cones display functional autonomy in vivo.	REFM 1 Bellen, Taylor, 2001: 236		
ID|FBrf0144676
TP|abstract
|Drosophila meeting abstract
MABST|Signaling molecules putatively involved with growth cone decisions have both
| cytoplasmic and nuclear downstream effectors. But the extent to which
| growth cone navigation and synaptogenic control is maintained locally, as
| opposed to transcriptionally from the cell body, remains largely unknown.
| To begin answering this question we used genetic and laser microbeam
| techniques to target and "guillotine" identified developing motor nerves
| (e. g. ISN) in live whole mount embryos. We cut motor nerves at a
| developmental stage in which they were still extending into the periphery,
| then allowed development to continue for at least 2 to 2.5 hours before
| fixing the embryos. Subsequent staining of the motor neurons showed that
| the dissociated growth cones had migrated into the periphery just as far
| as, but no farther than, the growth cones of neighboring hemisegments that
| had not been treated. Furthermore, axons from dissociated nerves were
| observed to turn toward appropriate target muscles. Thus, dissociated motor
| nerve growth cones are at least capable of migration and recognition of
| their target region in vivo.
AU|Siechen
|S.
AU|Chiba
|A.
YR|2001
TI|Axonal growth cones display functional autonomy in vivo.
JR|Bellen, Taylor, 2001
PG|236
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144677	AU 1 Simpson et al.	YR 1 2001	TP 1 Abstract	TI 1 Distinct axon behaviors controlled by the Robo family of receptors depend on their different cytoplasmic domains.	REFM 1 Bellen, Taylor, 2001: 237		
ID|FBrf0144677
TP|abstract
|Drosophila meeting abstract
MABST|In Drosophila, there are three roundabout genes that encode repulsive
| receptors for the Slit ligand, which is secreted by the midline glia. Robo
| plays the major role in governing whether axons do or do not cross the
| midline of the CNS; Robo2 assists with this function and assures that axons
| do not remain at the midline. Robo2 and Robo3 together determine the
| lateral position at which axons will extend in the longitudinal tracts.
| What are the differences between Robo and Robo2 that allow them to perform
| their distinct functions? One possibility is that Robo and Robo2 have
| different affinities for Slit. Indeed, Robo2 does bind to Slit with about
| twice the affinity of Robo, but this may not be sufficient to explain their
| functional differences. Alternatively, differences in their cytoplasmic
| domains might give Robo2 the ability to push axons laterally in the
| longitudinal tracts and Robo its ability to prevent axons from crossing the
| midline. To distinguish between these two possibilities, chimeric receptors
| were generated. The fact that Robo-extracellular + Robo-cytoplasmic
| chimeras can lateralize axons, while Robo2-extracellular + Robo-cytoplasmic
| chimeras cannot supports the hypothesis that the cytoplasmic domains are
| the essential regions specifying the distinct functions of Robo and Robo2.
| What are the important sequences in the cytoplasmic domains? Robo and Robo2
| share some conserved cytoplasmic motifs (the tyrosine phosphorylation sites
| CC0 and CC1) but over all have less than 30% homology. Expression of
| transgenes with some conserved domains deleted and half-chimeras where
| small sub-domains have been exchanged are further defining the critical
| regions. Robo can bind to Enabled but Robo2 cannot. Expression of a version
| of Robo that lacks the Ena -binding domain can shift the lateral position
| of axons, indicating that perhaps Ena binding prevents lateralization.
| There is also preliminary evidence that the phosphorylation state of the
| receptors can determine their activity. A version of Robo that cannot be
| phosphorylated on the second conserved tyrosine (CC1) has increased
| repulsive response to the midline but, like normal Robo, cannot push axons
| laterally. Further work on the way the cytoplasmic domains of the Robos
| affect the signaling efficacy for midline repulsion and lateral positioning
| will be presented.
AU|Simpson
|J.H.
AU|Rajagopalan
|S.
AU|Bashaw
|G.
AU|Bland
|K.S.
AU|Dickson
|B.J.
AU|Goodman
|C.S.
YR|2001
TI|Distinct axon behaviors controlled by the Robo family of receptors depend on their different cytoplasmic domains.
JR|Bellen, Taylor, 2001
PG|237
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144678	AU 1 Bhattacharya et al.	YR 1 2001	TP 1 Abstract	TI 1 Modulation of L-type calcium channels in Drosophila by pituitary adenylyl cyclase activating polypeptide.	REFM 1 Bellen, Taylor, 2001: 58		
ID|FBrf0144678
TP|abstract
|Drosophila meeting abstract
MABST|Modulation of calcium channels pl ays an important role in many cellular
| processes. Previous studies have shown that the L-type Ca 2+ channels in
| Drosophila larval muscles are modulated via a cAMP-PKA mediated pathway.
| This raises questions on the identity of the steps prior to cAMP,
| particularly the endogenous signal that may initiate this modulatory
| cascade. We now present data suggesting possible role of a neuropeptide,
| Pituitary Adenylyl Cyclase Activating Polypeptide (PACAP), in this
| modulation. Mutations in the amnesiac (amn) gene, which encodes a
| polypeptide homologus to human PACAP -38, reduced the L-type current in
| larval muscles. Conditional expression of a wild-type copy of the amn gene
| rescued the current from this reduction. Bath application of human PACAP-38
| also rescued the current, while it did not increase the wild-type current
| further. PACAP-38 did not rescue the mutant current in the presence of
| PACAP-6-38, a specific antagonist at type-I PACAP receptor (PAC1). 2',
| 5'-dideoxyadenosine (ddA), an inhibitor of adenylyl cyclase, inhibited
| PACAP-38 from rescuing the amn current. In addition, ddA reduced the
| wild-type current to the level seen in amn, while it failed to further
| reduce the current observed in amn muscles. H-89, an inhibitor of PKA,
| suppressed the effect of PACAP -38 on the current. The above data suggest
| that PACAP, the PAC1 receptors and AC play a role in the modulation of
| L-type Ca 2+ channels via cAMP-PKA pathway. The data also demonstrate a
| functional homology between human PACAP-38 and the amn gene product in Drosophila.
AU|Bhattacharya
|A.
AU|Lakhman
|S.S.
AU|Gu
|G.G.
AU|Singh
|S.
YR|2001
TI|Modulation of L-type calcium channels in Drosophila by pituitary adenylyl cyclase activating polypeptide.
JR|Bellen, Taylor, 2001
PG|58
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144679	AU 1 de Jong et al.	YR 1 2001	TP 1 Abstract	TI 1 Exploring the roles of Sidestep in motor axon targeting and synapse formation.	REFM 1 Bellen, Taylor, 2001: 238		
ID|FBrf0144679
TP|abstract
|Drosophila meeting abstract
MABST|Correct recognition of muscle targets by motor axons is central to
| successful formation of neuromuscular connectivity. In the embryonic
| Drosophila neuromuscular system most muscles are targeted by 2-3 motor
| axons. During larval stages these individual motor axons are readily
| distinguishable at the light microscope level on the basis of their bouton
| type. Hence the consequences of targeting behaviors in the embryo can be
| assayed in the larva. In the present study we have utilized
| gain-of-function analyses to uncover the role of Sidestep protein in
| facilitating targeting by different motor axon on a subset of muscles. When
| Side is overexpressed by all neurons during embryonic and larval stages,
| targeting choices and larval synapse growth are unaltered. Similarly when
| Side is overexpressed by all muscles across larval stages synapse growth is
| unaltered on these muscles however, there is a significant increase in the
| presence of terminals with type II boutons. The presence of type II
| innervation is further enhanced if overexpression in the muscles already
| commences during the embryonic stages. When overexpressed by a subset of
| muscles during embryogenesis and larval stages as many as 5 motor axons
| were observed on the muscle fiber with highest Side expression. The
| findings show that Side facilitates target selection by motor axons, and
| that this is dependent on the relative rather than the absolute protein
| level. We are extending our investigations to determine if Side can
| compensate for reduced Fasciclin II levels in the process of synapse stabilization.
AU|de Jong
|S.
AU|Cavallo
|J.
AU|Rios
|C.
AU|Sink
|H.
YR|2001
TI|Exploring the roles of Sidestep in motor axon targeting and synapse formation.
JR|Bellen, Taylor, 2001
PG|238
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144680	AU 1 Song and Salvaterra	YR 1 2001	TP 1 Abstract	TI 1 Analysis of neurotransmitter phenotype in transgenic Drosophila.	REFM 1 Bellen, Taylor, 2001: 59		
ID|FBrf0144680
TP|abstract
|Drosophila meeting abstract
MABST|The transgenic and genomic tools avail able for Drosophila make it an ideal
| system to investigate the nature of neurotransmitter phenotypes. The
| particular neurotransmitter used by a neuron is a fundamental way of
| classifying it, and is usually recognized by expression of genes involved
| in its biosynthesis, storage or release. Other genetic functions are likely
| to be associated with specific neurotransmitter phenotypes but these are
| largely unknown. We have constructed transgenic cholinergic and GABAergic
| fly lines using fluorescent reporter genes. The cholinergic line uses the
| 5' flanking DNA from the cholinergic gene locus (Cha and Vacht) fused to
| Gal4 and is recombined with a UAS-GFP (S65T) responder gene. The GABAergic
| line uses a direct promoter fusion of the Gad1 gene to RFP (Dsred1). The
| expression patterns of both reporters have been characterized and they are
| faithful to the know distribution of cholinergic and GABAergic neurons. In
| addition the Gad1-RFP lines mark all glutamatergic motor neurons, which are
| known to express GAD1 in Drosophila. Embryo cell cultures initiated form
| these transgenic lines express the fluorescent markers in specific
| non-overlapping subsets of cholinergic and GABAergic neurons. We have
| sorted these cells into specific populations of cholinergic and GABAergic
| neurons using fluorescence activated cell sorting. These isolated cells
| serve as a population of neurotransmitter specific mRNA which will be
| screened using Affymetrix whole Drosophila genome microarrays. Microarry
| data should thus allow a complete phenotypic definition of the particular
| genes uniquely expressed in neurons using a specific neurotransmitter.
| Supported by a grant form the NIH-NINDS.
AU|Song
|S.C.
AU|Salvaterra
|P.M.
YR|2001
TI|Analysis of neurotransmitter phenotype in transgenic Drosophila.
JR|Bellen, Taylor, 2001
PG|59
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144681	AU 1 Song et al.	YR 1 2001	TP 1 Abstract	TI 1 Methuselah, a putative G protein-coupled receptor, regulates excitatory neurotransmitter exocytosis at the larval neuromuscular junction of Drosophila.	REFM 1 Bellen, Taylor, 2001: 251		
ID|FBrf0144681
TP|abstract
|Drosophila meeting abstract
MABST|The methuselah (mth) gene encodes a heptahelical G protein-coupled receptor
| (GPCR) and has been identified through a genetic screen for mutations
| affecting life span in Drosophila 1 . The loss-of-function mutation mth 1
| extends life span by ~35% and enhances resistance to various forms of
| stress. However, nerve-evoked synaptic transmission is reduced at mth 1
| larval neuromuscular junctions by ~50%. This reduction is not due to a
| developmental defect because mth mutant NMJs show a normal number of
| presynaptic boutons. In addition, conditional, heat-shock-induced
| expression of Mth acutely increases synaptic transmission in wild type,
| suggesting a physiological role of Mth. The loss-of-function defect is
| located presynaptically and downstream from Ca 2+ entry because: (1)
| spontaneous occurring mEJP amplitudes are normal; (2) electrotonically
| elicited EJP amplitudes are reduced by ~50%; (3) stimulus-evoked
| intraterminal Ca 2+ levels (measured with Fluo-4) in type Ib boutons are
| normal; and (4) Ca 2+ channel-independent Ca 2+ ionophore-induced
| neurotransmitter release is reduced by ~50%. Consistent with
| loss-of-function defects, over -expression of Mth in motor neurons, but not
| in muscles, increases nerve-evoked synaptic transmission at wild type NMJs,
| suggesting a presynaptic origin of Mth signaling. Finally, we found that
| phorbol ester-induced facilitation of neurotransmitter release is markedly
| reduced in mth 1 , suggesting that Mth signaling is associated with the 2
| nd messenger diacylglycerol. The phorbol ester -induced facilitation of
| release is not mediated by protein kinase C but by an unknown effector
| protein. Together, our results reveal that Mth is a novel modulator of
| neurotransmitter release, regulating a step of exocytosis downstream from
| Ca 2+ entry.
AU|Song
|W.
AU|Ranjan
|R.
AU|Bronk
|P.
AU|Nie
|Z.
AU|Dawson-Scully
|K.
AU|Lin
|Y.J.
AU|Seroude
|L.
AU|Atwood
|H.L.
AU|Benzer
|S.
AU|Zinsmaier
|K.E.
YR|2001
TI|Methuselah, a putative G protein-coupled receptor, regulates excitatory neurotransmitter exocytosis at the larval neuromuscular junction of Drosophila.
JR|Bellen, Taylor, 2001
PG|251
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144682	AU 1 Spencer and Lnenicka	YR 1 2001	TP 1 Abstract	TI 1 Effect of reduced impulse activity upon the physiology of identified motor terminals in Drosophila larvae.	REFM 1 Bellen, Taylor, 2001: 60		
ID|FBrf0144682
TP|abstract
|Drosophila meeting abstract
MABST|Altered impulse activity has been shown to influence the development of
| motor terminal morphology in Drosophila larvae; however, the effect on
| synaptic physiology has not been directly examined. We have previously
| shown that reduced impulse activity decreases the size of synaptic boutons
| at larval motor terminals. To examine the effect of reduced impulse
| activity upon the physiology of identified motor terminals, we have used
| the temperature-sensitive paralytic mutants no action potential (nap) and
| temperature-induced paralysis E (tipE), which have reduced sodium channel
| activity. The rate of larval locomotion at 23 o C was reduced in nap (40.5%
| reduction) and nap; tipE (55.3% reduction) compared to Canton-S (CS),
| presumably due to a decrease in impulse activity. Combining nap with a
| duplication of the sodium channel gene, para, restored the rate of
| locomotion to CS levels. Synaptic potentials produced by axons 1 and 2 were
| recorded from muscle fiber 6 during 0.1 Hz stimulation of the nerve. The
| EPSP amplitude was significantly reduced in nap; tipE for both axon 1 (4.1
| �0.4 mV, n= 27) and axon 2 (16.0 �0.1 mV, n= 17) compared to CS (15.4 �1.9
| mV, n= 31 and 23.0 �2.0 mV, n= 23, respectively). However, EPSP amplitudes
| were not significantly different in nap compared to CS. The reduction in
| EPSP amplitude in nap; tipE does not appear to result from decreased motor
| terminal excitability. When action potentials were blocked with TTX and
| motor terminals were directly depolarized to evoke transmitter release, the
| maximum EPSP produced by combined depolarization of axon 1 and 2 was
| significantly less in nap; tipE (26.6 �1.3 mV, n= 13) compared to CS (35.0
| �1.6 mV, n= 30). We also examined synaptic transmission during
| high-frequency stimulation. Again, direct depolarization of the terminals
| was used since it was difficult to evoke action potentials in nap and nap;
| tipE nerves at high frequencies. Both nap and nap; tipE larvae showed
| greater synaptic depression than CS during 20 Hz stimulation for 60 sec. At
| the end of stimulation, EPSP amplitude was significantly smaller in nap
| (15.3 �1.2 mV, n= 7) and nap; tipE (10.7 �1.1 mV, n= 6) than in CS (23.0
| �2.9 mV, n= 7). In addition, the percentage decrease in EPSP amplitude
| during stimulation was significantly greater for nap (54.8 �4.2 %) and nap;
| tipE (57.2 �3.9 %) than for CS (33.3 �6.5 %). Thus, low impulse activity
| levels in Drosophila lead to small bouton size and prominent synaptic
| depression as previously demonstrated in other motor systems.
AU|Spencer
|G.M.
AU|Lnenicka
|G.A.
YR|2001
TI|Effect of reduced impulse activity upon the physiology of identified motor terminals in Drosophila larvae.
JR|Bellen, Taylor, 2001
PG|60
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144683	AU 1 St. Pierre et al.	YR 1 2001	TP 1 Abstract	TI 1 Regulation of neuropeptide expression and pathfinding by squeeze and rotund, two novel Kruppel-type zinc finger genes.	REFM 1 Bellen, Taylor, 2001: 239		
ID|FBrf0144683
TP|abstract
|Drosophila meeting abstract
MABST|We are investigating how neuronal cell identities are specified during
| Drosophila embryogenesis. Previous studies have shown that combinatorial
| expression of the Drosophila LIM-homeodomain (HD) transcription factors
| islet, lim3, and apterous controls the establishment of at least two
| fundamental aspects of neuronal identity, neuropeptide/ transmitter
| phenotype and axon pathfinding. We have identified a genetic interaction
| between some of these LIM-HD genes and two novel Kr�ppel-type zinc finger
| genes, squeeze (sqz) and rotund (rn), indicating that they may be acting
| together with LIM-HD genes to specify both motorneuron and interneuron
| identities. Both sqz and rn are expressed in subsets of CNS neurons. In
| some neurons they are coexpressed with each other and in other neurons they
| are coexpressed with LIM-HD genes. We will present data from loss and gain
| of function studies that implicate these two genes in regulation of
| neuropeptide expression and in pathfinding.
AU|St. Pierre
|S.E.
AU|Allan
|D.W.
AU|Thor
|S.
YR|2001
TI|Regulation of neuropeptide expression and pathfinding by squeeze and rotund, two novel Kruppel-type zinc finger genes.
JR|Bellen, Taylor, 2001
PG|239
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144684	AU 1 Stone and Posakony	YR 1 2001	TP 1 Abstract	TI 1 Analysis of an unusual allele of delta that acts as a dominant enhancer of Notch loss-of-function mutations.	REFM 1 Bellen, Taylor, 2001: 161		
ID|FBrf0144684
TP|abstract
|Drosophila meeting abstract
MABST|Typical loss-of-function alleles (or deficiencies) of Delta (Dl) (a) show
| mutually suppressive phenotypic effects when combined in double
| heterozygotes with Notch (N) loss-of-function mutations, and (b) fail to
| enhance the dominant bristle multiplication phenotypes of gain-of-function
| alleles of Bearded (Brd). The CS allele of Dl was recovered in an X-ray
| mutagenesis as a dominant enhancer of Brd 1 [Leviten and Posakony (1996).
| Dev. Biol. 176: 264-283]. In most respects Dl CS resembles a typical strong
| Dl hypomorph, but in addition to its unusual interaction with Brd, it acts
| as a strong dominant enhancer of the N haploinsufficient phenotype. In an
| attempt to understand the nature of these atypical interactions, and in
| particular to shed light on the possible functional relationship between
| Brd and Dl, we have determined the specific molecular lesion associated
| with the Dl CS allele, and are investigating how this mutant Dl protein
| differs in its behavior in vivo from the wild-type gene product.
AU|Stone
|T.
AU|Posakony
|J.W.
YR|2001
TI|Analysis of an unusual allele of delta that acts as a dominant enhancer of Notch loss-of-function mutations.
JR|Bellen, Taylor, 2001
PG|161
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144687	AU 1 Stortkuhl et al.	YR 1 2001	TP 1 Abstract	TI 1 Functional identification of olfactory receptor Or43a in D. melanogaster.	REFM 1 Bellen, Taylor, 2001: 141		
ID|FBrf0144687
TP|abstract
|Drosophila meeting abstract
MABST|59 candidate olfactory receptor (Or) genes have recently been identified in
| Drosophila melanogaster 1-3 . In wild type flies one Or (Or43a) is
| expressed at the distal edge of the third antennal segment in about 15
| olfactory receptor neurons (ORNs). To identify ligands for the receptor we
| used the Gal4/ UAS system to misexpress the olfactory receptor in the third
| antennal segment. Or43a-mRNA expression in the antenna of transformed and
| wild type flies was visualised by in situ hybridisation with a digoxigenin
| -labelled probe. Transformed lines were produced according to standard
| techniques. Two such lines were breaded with the Gal4 line GH320 that shows
| Gal4 expression exclusively in neurons of the third antennal segment.
| Progeny of this cross express the mRNA in additional cells in the antenna.
| 4 Or43a-mRNA is missexpressed in almost in olfactory receptor neurons in
| the third antennal segment. In order to analyse functional properties of
| the Or43a we reasoned that an increase of the number of ORNs specifically
| expressing the Or-mRNA, might also show an increased electroantennogram
| (EAG) to specific volatile substances, identifying them as specific
| ligands. Cyclohexanol, cyclohexanone, benzaldehyde and benzyl alcohol evoke
| increased EAGs while responses to ethyl acetate, propionaldehyde, butanol
| and aceton were not significantly different from wild type. This in vivo
| analysis reveals for the first time functional properties of one member of
| the recently isolated olfactory receptor family in Drosophila and will
| provide further insight into our understanding of olfactory coding. 1.
| Clyne, P. J. et al Neuron 22, 327-338 (1999). 2. Gao, Q. &amp; Chess, A.
| Genomics 60, 31-39 (1999). 3. Vosshall, L. B., Amrein, H., Morozov, P. S.,
| Rzhetsky, A. &amp; Axel, R. Cell 96, 725-736 (1999). 4. St�rtkuhl K. F.
| &amp; Kettler, R. (2001) PNAS in press
AU|Stortkuhl
|K.F.
AU|Kettler
|R.
AU|Wagner
|S.
AU|Hovemann
|B.T.
YR|2001
TI|Functional identification of olfactory receptor Or43a in D. melanogaster.
JR|Bellen, Taylor, 2001
PG|141
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144685	AU 1 Wagner et al.	YR 1 2001	TP 1 Abstract	TI 1 Drosophila glutathione-S-transferase gene cluster, GST-4, with expression in the olfactory organs.	REFM 1 Bellen, Taylor, 2001: 142		
ID|FBrf0144685
TP|abstract
|Drosophila meeting abstract
MABST|Glutathione-S-transferase (GST) belongs to a family of biotransformation
| enzymes that cooperate in clearing cells from toxic compounds[ 1].
| Detoxification is thought to proceed in two phases. In phase I a harmful
| chemical is transformed into a reactive species by dehydrogenases/
| reductases and enzymes of the P450 superfamily. In phase II polar groups
| are added by UDP-glucuronosyltransferase and Glutathione-S-transferase to
| render substances hydrophilic for elimination by secretion. Olfactory
| specific subclasses of GST have been found in vertebrates and
| invertebrates. In the moth Manduca Sexta antennal expression of GST has
| been attributed to detoxification and olfactory signal termination[ 2]. In
| Drosophila, two single GST gene loci at 53F, gst-2, and 55D, gst-3, and a
| cluster of eight genes at 87B, gst-1, have been described[ 3-5]. We report
| on a second large cluster of ten GST genes named gst-4 at the chromosomal
| locus 47. Using the enhancer trap technique we generated an olfactory
| mutant line, MS101a, with an abnormal behavioral and electroantennogram
| (EAG) response to ethyl acetate, acetone and propionaldehyde, but normal
| for acetic acid and ethyl alcohol. Defficiency mapping confirmed 2R47
| region as responsible for both, behavioral and EAG, mutant phenotypes.. In
| order to identify the affected gene we isolated the genomic DNA of the
| insertion site by rescue cloning and used it for screening an antennal cDNA
| library. Characterization and sequencing of the single cDNA clone obtained
| showed homology to GST genes. Using the Genscan program we identified 9
| additional GST genes nearby. The P-insertion in line MS101a interrupted the
| translational reading frame of the second gene, gst-3,2. X-gal and
| anti-lacZ-antibody staining of the MS101a line revealed expression in the
| olfactory organs of adults. 1. Salinas, A. E. and M. G. Wong, Glutathione
| S-transferases--a review. Curr Med Chem, 1999. 6( 4): p. 279-309. 2.
| Rogers, M. E., M. K. Jani, and R. G. Vogt, An olfactory-specific
| glutathione-S-transferase in the sphinx moth Manduca sexta. J Exp Biol,
| 1999. 202( Pt 12): p. 1625-37.
AU|Wagner
|S.
AU|Schwarzel
|M.
AU|Martin
|F.
AU|Alcorta
|E.
AU|Stortkuhl
|K.
AU|Hovemann
|B.T.
YR|2001
TI|Drosophila glutathione-S-transferase gene cluster, GST-4, with expression in the olfactory organs.
JR|Bellen, Taylor, 2001
PG|142
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144686	AU 1 Richardt et al.	YR 1 2001	TP 1 Abstract	TI 1 The Ebony protein in the Drosophila nervous system: Optic neuropil expression in glial cells.	REFM 1 Bellen, Taylor, 2001: 143		
ID|FBrf0144686
TP|abstract
|Drosophila meeting abstract
MABST|The Drosophila ebony mutation [1] reveals a pleiotropic phenotype with
| cuticular and behavioral defects. Mutant flies also exhibit reduced
| phototaxis and optomotor responses [2]. In order to understand Ebony
| function in the nervous system, particularly its role in transmission of
| the visual signal, it is essential to know the cell type and temporal
| characteristics of ebony expression throughout development. We therefore
| raised an antiserum against an Ebony peptide to detect the protein in whole
| mount and slice preparations of Drosophila. Ebony expression was detected
| from stage 12 of embryonic development, except for a gap of between 30 and
| 65 h after puparium formation. The labeling pattern obtained with Ebony
| antiserum in larvae and adults was similar to the expression pattern
| revealed by immunoreactivity to b-Galactosidase in ebony-lacZ fusion gene
| transformants [3]. Weak immunoreactivity was found in various parts of the
| brain, but strong labeling occurred in the lamina and distal medulla optic
| neuropiles. To identify cells expressing Ebony we double-stained with
| anti-Ebony in the glial marker line 3-66 [4] or with an antibody against
| Elav [5] specific for postmitotic neurons. Optic neuropile ebony expression
| was exclusively glial. Confocal microscopy of flies with
| photoreceptor-specific GMR-driven GFP expression in R1-R8, immunostained
| with anti-Ebony, indicated that Ebony-like immunoreactivity surrounds the
| terminals of R1-R6 in the lamina, just as the epithelial glia surround the
| lamina cartridges. This localization was confirmed by pre-embedding
| immuno-EM with Ebony antibody. The DAB reaction product localized to the
| epithelial glial cells [3]. Thus Ebony localized to sites surrounding
| photoreceptor terminals, and thus to sites where histamine release occurs
| during transmission of the visual signal. 1. Bridges CB, Morgan TH (1923)
| Carnegie Inst Wash 327: 50. 2. Heisenberg M (1972) In Information
| processing in the Visual Systems of Arthropods, R Wehner, Ed, Springer:
| Berlin, Heidelberg, New York. p. 265 -268. 3. Hovemann BT et al (1998) Gene
| 221: 1-9.
AU|Richardt
|A.
AU|Rybak
|J.
AU|Stortkuhl
|K.F.
AU|Meinertzhagen
|I.A.
AU|Hovemann
|B.T.
YR|2001
TI|The Ebony protein in the Drosophila nervous system: Optic neuropil expression in glial cells.
JR|Bellen, Taylor, 2001
PG|143
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144688	AU 1 Su et al.	YR 1 2001	TP 1 Abstract	TI 1 Activated MAPK is found adjacent to lateral neuron terminals and cycles in the dorsal brain.	REFM 1 Bellen, Taylor, 2001: 115		
ID|FBrf0144688
TP|abstract
|Drosophila meeting abstract
MABST|Output from the Drosophila central clock cells (lateral neurons) controls
| key circadian behaviors such as locomoter activity. Recently, we showed
| that mutations in the MAPK pathway disrupt cyclical locomoter activity
| suggesting a role for MAPK in a pathway that controls rhythmic behavior. In
| addition, the clock and neuropeptide mutants-tim 0 , per 0 -as well as a
| mutant that lacks a neuropeptide (PDF) released specifically by lateral
| neurons show decreased activated MAPK (phosphoMAPK) levels. Using
| antibodies directed against phosphoMAPK, we performed immunoflourescence on
| adults to determine the site of MAPK activation in the circadian system.
| Immunoflourescence demonstrated high levels of phosphoMAPK in CNS regions
| adjacent to the lateral neuron projections. Cycling of phosphoMAPK is seen
| in the dorsal brain region, an anatomical locale that recei ves lateral
| neuron input and is thought to be important for activity. The temporal
| activation of MAPK mirrors the reported cycling of PDF neuropeptide
| release. These data suggest that signaling of MAPK activation may be a
| direct effect of PDF.
AU|Su
|H.S.
AU|Williams
|J.A.
AU|Field
|J.
AU|Sehgal
|A.
YR|2001
TI|Activated MAPK is found adjacent to lateral neuron terminals and cycles in the dorsal brain.
JR|Bellen, Taylor, 2001
PG|115
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144689	AU 1 Suster and Sokolowski	YR 1 2001	TP 1 Abstract	TI 1 Scribbler is required in central interneurons to specify Drosophila larval motor pattern.	REFM 1 Bellen, Taylor, 2001: 162		
ID|FBrf0144689
TP|abstract
|Drosophila meeting abstract
MABST|Drosophila larvae show a stereotypic pattern of locomotion on a plain agar
| substrate, alternating between long episodes of straight movement and brief
| episodes of pausing and turning. The neural circuitry underlying this
| relatively simple motor pattern is unknown. Using a computer-assisted
| motion analysis system 1 we show here that third instar larvae from several
| independent mutant alleles of scribbler 2 , display increased turning rates
| and reduced speed. A developmental analysis of a hypomorphic sbb allele (l(
| 2) 03432) shows that this abnormal motor pattern first appears between 24
| and 52 hrs after larval hatching, and that it results specifically from an
| increase in turning rates and pausing times. Immunostainings show that
| SCRIBBLER (SBB) is localized to the nucleus of all neur ons, muscle, and
| imaginal tissues. Expression of the small or large sbb transcripts under
| GAL4/ UAS control in the nervous system (elav-GAL4) or in interneurons
| alone (cha-GAL4) is sufficient to rescue the locomotor and neuroanatomical
| defects of sbb 03432 mutant third instar larvae. In contrast, expression of
| sbb in the PNS alone (P0163-GAL4) or in motorneurons ( ftz ng20 -GAL4) does
| not rescue the turning deficits of sbb 03432 mutant larvae. Although larvae
| from most sbb alleles display a variety of developmental (reduced growth
| and delay) and neural deficits (reduced brain size and abnormal nerve
| cord), larvae carrying a viable ep( UAS) insertion in sbb, ep( 2) 0328,
| show high turning rates and reduced speed, whilst its nervous system and
| overall morphology is indistinguishable from wild type. A leaky hs-sbb
| insertion in the sbb 03432 mutant background rescues the abnormal turning
| deficits but not the developmental deficits associated with this mutation.
| Current work combining genetic analysis and electrophysiology is in
| progress to elucidate how scribbler functions in central interneurons to
| specify the larval motor pattern. 1 Suster, M. L. PhD Thesis, University of
| Cambridge, 2001. 2 Yang et al (2000) Genetics 155: 1161-1174.
AU|Suster
|M.L.
AU|Sokolowski
|M.B.
YR|2001
TI|Scribbler is required in central interneurons to specify Drosophila larval motor pattern.
JR|Bellen, Taylor, 2001
PG|162
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144690	AU 1 Sweeney and Davis	YR 1 2001	TP 1 Abstract	TI 1 Diphthong: a transmembrane protein involved in the homeostatic regulation of synaptic structure and fucntion at the Drosophila neuromuscular junction.	REFM 1 Bellen, Taylor, 2001: 240		
ID|FBrf0144690
TP|abstract
|Drosophila meeting abstract
MABST|During development a regulated increase in presynaptic structure and
| function compensates for increased muscle size in order to achieve constant
| muscle depolarisation. This precise coupling of pre-and postsynapic
| development is a form of homeostatic regulation that ensures appropriate
| muscle excitation during a period of rapid muscle growth. Previous
| experiments have demonstrated that homeostatic regulation of synaptic
| structure and function involves a trans-synaptic signaling system from
| muscle to nerve. In a genetic screen for components of this trans-synaptic
| signaling system we identified a novel gene call diphthong. Diphthong
| loss-of-function mutations lead to an overgrowth of the neuromuscular
| synapse (50-150% increase in bouton number) indicating that diphthong may
| be a negative regulator of synaptic growth. An electrophysiological
| analysis demonstrates that synaptic function is normal despite the large
| increase in synapse size. The diphthong transcript is expressed in the late
| embryonic nervous system. Diphthong encodes a multi-transmembrane domain
| protein, homologs of which are also found in humans, mouse and C. elegans.
| We are currently exploring genetic interactions with the highwire gene, a
| recently indentified negative regulator of synaptic growth at the
| neuromuscular junction. This work is supported by a Wellcome Trust Prize
| Travelling Fellowship to S. T. S., a BWF Young Investigator Award and NIH
| Grant # 44908-32374 to GWD.
AU|Sweeney
|S.T.
AU|Davis
|G.W.
YR|2001
TI|Diphthong: a transmembrane protein involved in the homeostatic regulation of synaptic structure and fucntion at the Drosophila neuromuscular junction.
JR|Bellen, Taylor, 2001
PG|240
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144691	AU 1 Takeuchi et al.	YR 1 2001	TP 1 Abstract	TI 1 Defective expression of Drosophila homolog of dystroglycan in a cryophilic mutant, atsugari.	REFM 1 Bellen, Taylor, 2001: 199		
ID|FBrf0144691
TP|abstract
|Drosophila meeting abstract
MABST|For poikilothermic species, behavior plays a major role in thermoregulation;
| a wide variety of animals sense the environmental temperature and move
| towards to thermally comfortable zone. A variety of animals show a large
| difference in temperature preference that is also modified by th eir
| thermal experiences. We show that the temperature preference of Drosophila
| larvae was modified by their growth temperature. The larvae changed
| physical structure of membrane during thermal adaptation and their
| preferred temperature was highly correlated with the membrane lipid
| ordering states and the contents of unsaturated fatty acids in membrane
| lipids. In order to further study the molecular mechanisms of
| thermoregulation, we have screened P-element-tagged lines for mutants with
| aberrant thermoregulatory behaviors. A mutant, named atsugari, showed the
| significant increase in membrane fluidity and strong low-temperature
| preference. The gene affected by the P-element insertion turned out to be
| Drosophila homologues of dystroglycan (Dg), a transmembrane protein that
| forms the core of dystrophin -glycoprotein complex, which is defective in
| Duchenne muscular dystrophy. Dg showed widespread expression in glial and
| epithelial cells. Further genetic and biochemical analyses of atsugari have
| been undertaken to c larify the role of Dg in thermoregulation.
AU|Takeuchi
|K.
AU|Aizu
|M.
AU|Kaneda
|M.
AU|Yamaguchi
|A.
AU|Fujii
|H.
AU|Tamamoto
|D.
AU|Umeda
|M.
YR|2001
TI|Defective expression of Drosophila homolog of dystroglycan in a cryophilic mutant, atsugari.
JR|Bellen, Taylor, 2001
PG|199
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144692	AU 1 Colonques et al.	YR 1 2001	TP 1 Abstract	TI 1 Minibrain is involved in proliferation and determination of adult CNS neurons.	REFM 1 Bellen, Taylor, 2001: 200		
ID|FBrf0144692
TP|abstract
|Drosophila meeting abstract
MABST|The Minibrain (Mnb) gene encodes a new protein kinase family involved in
| postembryonic neurogenesis (1). Defined areas in the brain of viable adult
| Mnb flies are greatly reduced in size but no gross alterations in neuronal
| architecture is found. This phenotype results from a decrease in the number
| of neurons that are produced during the postembryonic proliferation. This
| suggests a role of Mnb in neuronal proliferation at specific brain regions.
| We have here analyzed the cellular basis of the functional role of Mnb on
| proliferation and neurogenesis. According to the described phenotype, Mnb
| expression is observed specifically in the proliferative centers of the
| larval brain. Pulse-chase BrdU-labeling experiments carried out along
| larval development let us conclude that Mnb mutations cause neither
| decrease in the number of proliferating Nbs nor modifications in the timing
| of their proliferation. However, the number of BrdU-labelled neurons that
| were chased in the adult brain after a pulse at late third instar larvae
| was clearly reduced in the optic lobes of Mnb flies. Acridine Orange
| staining and EM techniques allowed detection of apoptosis at the optic lobe
| proliferation centers of Mnb third instar larvae. Nevertheless, the
| extension of this neuronal cell death can not by itself explain the
| decrease of neuron number observed in adult Mnb mutants. Furthermore, we
| have analyzed the pattern of expression of Mnb transcripts and the pattern
| of division of larval brain Nbs (2) in Mnb mutants. Finally, the phenotype
| generated by overexpression of Mnb, and the study of cell cycle properties
| of Mnb mutants, were studied. Altogether, these studies let us conclude
| that Mnb is involved in the proliferation of postembryonic Nbs and the
| determination of postmitotic neurons. (1) Tejedor et al, (1995) Neuron 14,
| 287-301 (2) Ceron J, Gonzalez C and Tejedor FJ( 2001) Dev. Biol. 230, 125� 138
AU|Colonques
|J.
AU|Bieri
|G.
AU|Vera
|E.
AU|Hammerle
|B.
AU|Ceron
|J.
AU|Tejedor
|F.J.
YR|2001
TI|Minibrain is involved in proliferation and determination of adult CNS neurons.
JR|Bellen, Taylor, 2001
PG|200
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144693	AU 1 Tello et al.	YR 1 2001	TP 1 Abstract	TI 1 Molecular characterization of the Drosophila homolog of atypical PKCz: Implications for its role in memory formation.	REFM 1 Bellen, Taylor, 2001: 116		
ID|FBrf0144693
TP|abstract
|Drosophila meeting abstract
MABST|Persistent kinase activity is an attractive candidate mechanism for
| mediating the changes in synaptic transmission that underlie memory
| consolidation. Synaptic activity induces a persistently activated form of
| PKCz, known as PKMz, which lacks the N-terminal regulatory domain. We have
| shown that induction of expression of mammalian PKMz shortly after training
| results in memory enhancement in Drosophila melanogaster (see abstract by
| Drier et al ). A single homolog of the atypical PKCz gene in Drosophila,
| DaPKC, has been identified. We report here our advances in the molecular
| characterization of endogenous DaPKC and its role in memory formation.
| Antibodies raised against specific domains, revealed distinct isoforms of
| the protein, including a putative DaPKM form, which is predominantly
| detected in heads. Northern blot and RT-PCR analyses disclosed very
| interesting alternative splicing patterns of the gene. The observed
| transcripts differ in their transcription initiation sites (and hence,
| promoter regions), and distribution throughout the organism. Interestingly,
| two transcripts missing the N-terminal domain are found almost exclusively
| in heads. Moreover, Ca ++ and DAG-independent kinase activity
| characteristic of atypical PKCs, is increased in head extracts, but not
| observed in extracts from bodies. Further analysis of DaPKC transcripts,
| their regulation and protein products is in progress. Finally, we are
| investigating protein interactions with the distinct DaPKC isoforms, which
| should shed some light on the role of DaPKM in memory formation.
AU|Tello
|M.K.
AU|Drier
|E.A.
AU|Wu
|P.
AU|Carey
|A.
AU|Yin
|J.
YR|2001
TI|Molecular characterization of the Drosophila homolog of atypical PKCz: Implications for its role in memory formation.
JR|Bellen, Taylor, 2001
PG|116
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144694	AU 1 Allan et al.	YR 1 2001	TP 1 Abstract	TI 1 Specification of neuronal identities by LIM-HD, POU and zinc finger transcription factors.	REFM 1 Bellen, Taylor, 2001: 12		
ID|FBrf0144694
TP|abstract
|Drosophila meeting abstract
MABST|We are interested in understanding how neuronal cell identities are
| specified during embryogenesis. Previous studies have shown that the LIM
| homeodomain (LIM-HD) transcription factors islet, lim3 and apterous are
| expressed in subsets of neurons in the ventral nerve cord. Functional
| analysis further indicated that these genes act in combinatorial codes to
| control both axon guidance and neurotransmitter expressi on. However, none
| of these transcription factors are expressed exclusively in a single
| neuronal cell type and, most likely, the specific function of LIM-HD
| proteins is dependent upon additional nuclear factors present within each
| neuronal cell type. To this end we have identified co-expression and
| genetic interactions between these LIM-HD genes and transcription factors
| of the POU and Kr�ppel families. Specifically, a member of the POU family,
| drifter, is co-expressed with islet and lim3 in ISNb motor neurons. Genetic
| interaction and misexpression studies indicate that drifter acts in
| combination with islet and lim3 to specify ISNb motor neuron sub-class
| identity. There is precedence for direct physical interactions between
| LIM-HD and POU proteins, we are conducting experiments to elucidate whether
| these proteins may form complexes. We have furthermore identified genetic
| interactions between LIM-HD genes and two novel Kr�ppel-type zinc finger
| genes, rotund and squeeze. In the embryo, expression of rotund and squeeze
| is largely confined to the CNS. rotund is co-expressed with islet and lim3
| in subsets of anterior motor neurons and squeeze is co-expressed with
| apterous in thoracic FMRFamide expressing cells. Mutant analysis indicate
| that rotund and squeeze may be acting in combination with LIM-HD genes to
| specify neuronal cell identities.
AU|Allan
|D.W.
AU|Certel
|S.J.
AU|St. Pierre
|S.E.
AU|Johnson
|W.A.
AU|Thor
|S.
YR|2001
TI|Specification of neuronal identities by LIM-HD, POU and zinc finger transcription factors.
JR|Bellen, Taylor, 2001
PG|12
TP|abstract
}
# EOR
REFR
{
RETE|ID 1 FBrf0144695	AU 1 Todi and Eberl	YR 1 2001	TP 1 Abstract	TI 1 Effects of myosin VIIa mutants in Drosophila hearing.	REFM 1 Bellen, Taylor, 2001: 144		
ID|FBrf0144695
TP|abstract
|Drosophila meeting abstract
MABST|Mutations in myosin VIIa, an unconventional myosin, cause human Usher 1B
| syndrome, characterized by sensorineural deafness, balance anomalies and
| retinitis pigmentosa. Myosin VIIa is localized in the hair cells of the
| vertebrate inner ear, specifically in the cuticular plate and stereocilia.
| Putative functions of vertebrate myosin VIIa include the spatial
| organization of the stereocilia and kinocilia of the hair cells and opsin
| transport in photoreceptors; myosin VIIa is also present in adherens
| junctions. The Drosophila homolog of myosin VIIa is crinkled (ck). Previous
| studies have shown that ck mutations lead to abnormalities in wing prehair
| formation and elongation. Multiple hairs are observed, often branched and/
| or bent. We tested for effects of ck mutations in Drosophila hearing,
| mediated by Johnston's organ, a cluster of about 100 chordotonal sensilla
| in the second antennal segment. Electrophysiological data indicate that ck
| mutant combinations disrupt hearing by abolishing (ck 1 /ck 13 ), or
| significantly reducing the amplitude of ( ck 1 /ck 07130 and ck 13 /ck
| 07130 ), sound-evoked compound action potentials in the antennal nerve.
| Electron microscopy studies are underway to reveal possible morphological
| defects that may explain the observed electrophysiology. To address the
| specificity of these effects, we also tested another class of ciliated
| mechanoreceptors, the bristle organs. Bristles in ck mutants are shorter
| than normal, and their response to mechanical stimulation appears to lack
| the usual