Vulval development in C. elegans serves as powerful paradigm to understand the
interplay of diverse signal transduction pathways during organogenesis. Previous studies
have demostrated that the canonical Wnt signaling pathway plays a pivotal role in the
development of the vulva in C. elegans and helps in establishing the 20-10-20 vulval
induction pattern of the vulval precursor cells (VPCs). The main focus of my masters
research project was to get an understanding of how this vulval induction pattern,
established in response to Wnt signaling has evolved in other closely nematode species,
particularly C. briggsae. We fmd that the Wnt signaling pathway has evolved to
positively as well as negatively regulate the competence of VPCs in C. briggsae. We
demonstrate that while mutations inpry-1/Axin in C. elegans result in Multivulva (Muv)
phenotype, mutations in the C. briggsae pry-1 gene give rise to a novel MultivulvaVulvaless
(Muv-Vul) phenotype. This phenotype is characterized by VPCs anterior to
P6.p frequently adopting induced cell fates while those posterior to P6.p frequently adopt
a non-induced fate. Furthermore, we also show that the functioning of the Wnt signaling
pathway in C. briggsae is dependent upon the activity of key regulators of the Wnt
pathway such as the TCFILEF-1 family member pop-1, the f3-catenin bar-] and the hox
gene lin-39. Taken together, the fmdings from this study show that while a conserved
canonical Wnt pathway confers competence on VPCs in both C. elegans and C. briggsae,
the final outcome nonetheless seems to have diversified. / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/21734 |
| Date | 05 1900 |
| Creators | Seetharaman, Ashwin |
| Contributors | Gupta, Bhagwati, Biology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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