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Poster Full Abstracts - Neural Development
Poster board number is above title. The first author is the presenter
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feeding, perturbed levels of neuronal DA during development affect both 5-HT innervation of the gut as well as larval feeding behavior. In addition,
although feeding does not differ in male and female larvae, it is differentially sensitive to the trophic, or developmental, actions of neuronal 5-HT and DA,
evidence that the developing brain is sensitive to the hormonal environment. Using transgenic approaches, we have manipulated the sexual identity of the
brain and the fat body (a sexually dimorphic tissue that secrete hormones) during CNS development. Our preliminary studies have established that the sexual
identity of these tissues are sensitive to the actions of DA and 5-HT function during CNS development. Funded by National Science Foundation Grant No.
0616062 and The President’s Fund, Saint Louis University.
673A
jim lovell, a BTB-POZ domain protein implicated in neural differentiation and embryonic pattern formation.
Kathleen M. Beckingham, Sonia
Bjorum, Rebecca A. Simonette, William J. Deery, Raul Alanis, Benjamin Lewis. Dept Biochem & Cell Biol, Rice Univ, Houston, TX.
jim lovell
(
lov
), CG16778, encodes a transcription factor with a BTB (
Broad
,
tramtrack
,
bric-a brac
) dimerization domain.
lov
mutations
lov47
and
lov66
delete adjacent DNA in the 5’ flank of three of the
lov
transcripts and produce different phenotypes.
lov47
produces enhanced sensitivity to larval crowding
and defects in male courtship. In contrast,
lov66
shows no behavioral defects but has reduced female fertility associated with dorsal appendage
abnormalities. All four
lov
transcripts encode the same protein. Thus we have used a Lov antibody and RT-PCR to investigate
lov
expression and determine
the effects of
lov47
and
lov66
on
lov
transcripts. The
lov
transcripts show highly individual expression patterns. Transcript A is testis-specific, but our
antibody gives no distinctive expression pattern in the testis. Transcript C is expressed in early embryogenesis. Our antibody shows that this expression
results in a “stripey” pattern of Lov protein, like the pair rule patterns, and later, in accumulation of Lov in the amnioserosa. Transcripts B and D are
responsible for neural-specific expression that begins late in embryogenesis. In the PNS, Lov is found in subsets of chordotonal and external sensory
neurons, suggesting that Lov acts to differentiate individual neurons within a given class.
lov66
results in ectopic expression of
lov
transcripts in the ovary
and disrupted expression of
Broad
, a determinant of dorsal appendage fate, in ovarian follicle cells. Given that Broad is a
lov
-related BTB transcription
factor, we hypothesize that
lov66
disrupts chorion development by interfering with Broad activity. In contrast,
lov47
results in loss of expression of the
neural transcript D. The behavioral phenotypes associated with
lov47
presumably reflect loss of this transcript.
lov47
and
lov66
probably delete different
regulatory elements associated with the gene. Supported by NASA Grant NNX09AH43G.
674B
Identification of a novel suppressor of Crumbs and its role in growth regulation.
Eunbyul Yeom, Kwang-Wook Choi. Department of Biological
Sciences, Graduate School of Nanoscience and Technology, KAIST, Daejeon, South Korea.
Crumbs (Crb) is a transmembrane protein which regulates the apical-basal polarity in
Drosophila
. Recent studies have shown that Crb is also involved in
growth control by regulating the Hippo signaling pathway. To gain further insights into the intracellular function of Crb, we screened a set of RNAi lines for
genetic modifiers of the eye phenotype caused by overexpression of the Crb intracellular domain (Crb
intra
). RNAi knockdown of one of these modifiers
labeled as Su(Crb) strongly suppressed the Crb
intra
phenotype. The C-terminal half of this gene is highly conserved in metazoan species, but no specific
function has been identified yet. To investigate the biological function of Su(Crb), we generated loss-of-function mutant lines by imprecise excision of an
adjacent P-element insert. Two mutant alleles Su(Crb)
Δ52
and Su(Crb)
Δ182
, are likely to be null, as they are deficient in almost entire coding sequence.
Su(Crb) homozygotes also suppressed the Crb
intra
eye phenotypes and they have physical interaction in vitro. These data suggest that the genetic interaction
between Crb and Su(Crb) is specific. Su(Crb) mutants are semi-lethal, as they die during different stages while adult escapers show low fecundity and
reduced lifespan. Dying mutant animals show severe developmental defects. Taken together, our study suggests that Su(Crb) is a novel component that
functions in the Crb pathway necessary for growth regulation.
675C
scalloped expression during Drosophila embryogenesis.
Michael Benson
1
, Nicholas Gubitosi
1
, Elizabeth Norris
1
, Chelsea Gurvis
1
, Elena Brandano
1
,
Karrie Brondell
1
, Rachel Yonker
1
, James Skeath
2
, Kirsten Guss
1
. 1) Biology, Dickinson College, Carlisle, PA; 2) Genetics, Washington University School of
Medicine, St. Louis, MO.
scalloped (sd)
functions with
vestigial (vg)
to control wing development in Drosophila melanogaster. To characterize the expression of
sd
in other tissues
during fly embryogenesis, we employed whole mount immunodetection of an antibody that we developed for the corresponding protein. We show that SD
expression becomes localized to subsets of cells in the central and peripheral nervous systems and limb primordia as embryogenesis proceeds. In the ventral
nerve cord, SD expression overlaps with that of VG in neuroblast 1-2 descendants and the ventral unpaired median motorneurons. This work provides the
necessary descriptive foundation for functional studies regarding the role of
sd
during development of the Drosophila central nervous system.
676A
CHARACTERIZATION OF
aaquetzalli (aqz)
, A GENE REQUIRED FOR DEVELOPMENT OF THE NERVOUS SYSTEM DURING
Drosophila
melanogaster
EMBRYOGENESIS.
Miguel Mendoza-Ortiz, Juan Riesgo-Escovar. Dep. de Neurobiología del Desarrollo y Neurofisiología, Inst.
Neurobiología, UNAM, Campus Juriquilla, Querétaro, México.
The gene
aqz locus
encodes pioneer proteins with limited homology.
aqz
is requiered for nervous system formation, since
aqz
mutants die as embryos with
malformed nervous system. The name
aaquetzalli
derives from the fan-shaped appearance of mutant cuticles, also affected, as
aaquetzalli
is the Nahuatl
word for fan.
aqz
expression occurs at all stages of the
Drosophila melanogaster
life cycle, and is dynamic. Mutant analysis of
aqz
in epidermal and nervous
tissues reveal early defects implying a function in early ectoderm differentiation into epidermis and nervous system:
aqz
mutant alleles have anterior, dorsal
and ventral holes in the embryonic epidermis, as well as central nervous system malformations and faulty axons and commisures, plus loss of peripheral
nervous system. We analyzed if these mutants exhibit deficits during neural stem cell formation. Using neural stem cell markers like Deadpan (Dpn) for
neuroblasts and Even Skipped (Eve) for ganglion mother cells (GMC), we showed that
aqz
mutant embryos present severe neural stem cell defects in the
ventral and procephalic regions. In most cases, we document spotty hyperplasia of neural stem cells and a parallel loss of epithelium. This neural stem cell
phenotype resembles the Notch-Delta neurogenic phenotype, so we have conducted genetic interactions with this pathway. Results imply that
aqz
interacts
with this pathway.