Poster abstracts

Poster number 58 submitted by Allison Webb

Pax/EGL-38 cell-specific functions in the C. elegans uterine ventral cells

Allison Webb (OSBP), Ryan Johnson (MG), Helen Chamberlin (MG)

Abstract:
Paired-box (PAX) transcription factors are known regulators of coordinated development. Despite the broad biological requirements for PAX, its activities in coordinating organogenesis between neighboring, disparate cells are not well understood. To investigate PAX function, we are utilizing a Caenorhabditis elegans ortholog, EGL-38. In C. elegans, EGL-38 is required both in the epidermal, vulval vulF cells and the mesodermal, uterine uv1 cells. EGL-38 is known to function in the vulF cells to specify uv1 cell identity, and we believe that EGL-38 is functioning within the uv1 cells to activate a battery of neuropeptide genes required for egg-laying. We have identified two uv1 neuropeptides genes, nlp-2 and nlp-7, whose expression is dependent on EGL-38 activity in the uv1 cells. An nlp-2 PAX binding element (nre1) has been shown to be required for Pnlp-2 reporter expression and to be bound by the EGL-38 DNA binding domain in vitro; we are currently using site-directed mutagenesis to investigate a similar region of DNA in the nlp-7 promoter as an EGL-38 binding site. We are also investigating the role of EGL-38 in egg-laying by examining the impact on egg retention in nlp-2, nlp-7, and flp-11 (an additional neuropeptide) mutants. A role for EGL-38 to activate targets which participate directly in a biological function such as egg-laying has not previously been identified, and we hope to expand the understanding of PAX protein function in general through this work.

Keywords: Developmental Biology, Genetic program, PAX protein