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Poster Full Abstracts - Cell Biology and Signal Transduction
Poster board number is above title. The first author is the presenter
207
provide new insights into how the destruction complex down regulates Wnt signaling in development and disease.
281B
Frizzled 2 is critical for the regulation of vitellogenesis in the mosquito Aedes aegypti.
Shin-Hong Shiao. Department of Parasitology, National Taiwan
University, Taipei, Taipei, Taiwan.
Mosquito-borne diseases are the most devastating agents for human being, due to its high diversity of transmissible pathogens like protozoan and viruses.
Despite the efforts from government agencies that have contributed the eradication of the mosquito-borne diseases for several decades, the goal has not been
achieved yet. Therefore, many research institutes turn their attentions toward the mosquito life cycle and immune system to halt the disease transmission.
Previous studies have already demonstrated that Target of Rapamycin (TOR) pathway plays an important role in mosquito vitellogenesis, whereas WNT
pathway participates in the embryonic development and cell polarity. However, the interactions between these pathways are poorly understood. In this study,
we propose a hypothesis that factors of TOR and WNT signaling pathway play synergistically in the mosquito vitelloginesis. We attempt to characterize
WNT signaling components in the mosquito, Aedes aegypti. Our results showed that silencing of Frizzled2 (FZ2), a transmembrane receptor of WNT
signaling pathway, and TOR resulted in the decrease of Aedes aegypti survival fitness against S. aureus and E. coli infection. Interestingly, the oviposition
ability has been altered in the absence of FZ2. Also, we demonstrated that FZ2 is highly expressed in the mosquito fat body at 6 hours post blood meal in
turns of transcriptional and translational level, suggesting the amino acid-stimulated feature of FZ2. The transcriptional expression of TOR is reduced in the
absence of key components in the WNT pathway. Our results showed that Frizzled 2 is critical in the regulation of mosquito vitellogenesis.
282C
A screen for mutations that affect Drosophila eye development identifies new regulators of signaling pathways.
Annabelle Y.T. Suisse
1
, Josepha
Steinhauer
1,2
, Jessica E. Treisman
1
. 1) Developmental Genetics, Skirball Institute of Biomolecular Medicine, New York, NY; 2) Department of Biology,
Yeshiva University, New York, NY.
The
Drosophila
eye provides a remarkable system to study the processes of cell growth, differentiation, and death that drive tissue specification and
morphogenesis. All these processes are governed by cell signaling pathways that are highly conserved among vertebrates and invertebrates. We have carried
out a mosaic genetic screen to discover genes required for the normal pattern of photoreceptor differentiation. The genes characterized so far include
components of the Hedgehog (Hh), Wingless (Wg), Epidermal Growth Factor Receptor (EGFR) and Notch signaling pathways. We are currently
characterizing additional mutations that appear to affect these signaling pathways. One such mutation,
7D9
, completely prevents differentiation of
photoreceptors. Target genes of both the Wg and Hh pathways are ectopically activated in the mutant clones. Moreover, the mutant cells are enlarged.
Another complementation group consisting of two alleles is required for normal expression levels of the neuronal nuclear protein Elav and the Hh target
gene
decapentaplegic
, but does not affect
patched
, another Hh target gene. Cells homozygous for these mutations also strongly upregulate the EGFR target
gene
argos
. Identifying the genes affected by these mutations and determining their molecular mechanisms of action will improve our understanding of the
functions of signaling pathways that act in eye disc patterning, and the interactions between them.
283A
Role of kinesin II - Armadillo interaction in Wingless signaling pathway.
Linh Thuong Vuong, Kwang Wook Choi. Department of Biological Sciences,
KAIST, Graduate School of Nanoscience and Technology, Daejeon, Korea.
The
Drosophila
kinesin II motor subunit encoded by Klp64D is involved in the axonal transport of choline acetyltransferase and the formation of
chordotonal sensory cilia (
Sarpal et al., 2003
). Our previous study revealed a new role for Klp64D in the localization of adherens junction (AJ) proteins,
Armadillo (Arm) and Bazooka (Baz), during photoreceptor morphogenesis in the eye (
Mukhopadhyay et al., 2010
). Since Arm is an important component in
Wingless (Wg) signaling pathway, we tested whether Klp64D is involved in Wg signaling. Here we show that Arm forms a protein complex with Klp64D by
binding to the motor’s cargo domain. To study the function of this interaction, we tested whether Klp64D is required for Wg - Arm signaling in the wing
imaginal disc that is critical for the wing outgrowth. We show that clonal loss of Klp64D in wing discs causes a reduced Wg expression at the dorsoventral
border. Further, loss of Klp64D function in the wing resulted in defective wing margin bristles and notching of the wing. We also provide evidence for
strong genetic interaction between Klp64D and Arm in the wing and eye. Taken together, our data suggests that kinesin II - dependent transport Arm is
required for Wg signaling.