Poster abstracts
Poster number 5 submitted by Allison Webb Chasser
EGL-38 coordinates development in the Caenhorhabditis elegans egg-laying system through EGF pathway dependent and independent functions
Allison Webb Chasser (OSBP), Ryan Johnson (OSU Molecular Genetics), Helen Chamberlin (OSU Molecular Genetics)
Abstract:
Development of the egg-laying system in C. elegans relies upon reciprocal signaling by EGF, which is used first by the somatic gonad to induce vulval cell fates, and then by vulval progeny cells to signal back to the uterine uv1 cells, which anchor the vulva to the uterus. Previous genetic experiments have shown that the Pax2/5/8 ortholog EGL-38 is necessary for vulval EGF expression and for uv1 cell specification; however, it has remained unclear whether EGL-38 has functions in both the vulva and uv1 cells, or if it functions through a linear pathway of activation. Using CRISPR-mediated genome editing, we have created an endogenously-tagged EGL-38::GFP protein by which we have confirmed that EGL-38 is expressed in both the vulval and uv1 cells at the appropriate times to be active in EGF pathway activation (vulF) and response (uv1). Genetic disruption and chemical inhibition studies have shown that not only is egl-38 expression in uv1 dependent on the EGF pathway, but EGL-38 has additional autonomous functions within uv1 to activate expression of two neuropeptide-like proteins, one of which has a confirmed role in controlling the periodicity of egg-laying. Taken together, our results demonstrate that EGL-38 has both EGF pathway independent and dependent functions within the uv1 cells for coordination of the egg-laying system. These findings present a novel mode of Pax function, wherein Pax transcription factor participates in, or is responsive to, the developmental coordination between two tissues.
Keywords: Development, Cell differentiation, Pax transcription factor