Poster abstracts
Poster number 14 submitted by Allison Webb
PAX protein coordination of cell fate and organogenesis in Caenorhabditis elegans
Allison Webb (OSBP), Ryan Johnson, Helen Chamberlin (OSU Molecular Genetics)
Abstract:
Paired box (PAX) transcription factors are essential regulators of development that function in diverse cell types of adjacent tissues to coordinate growth and differentiation of cells into a cohesive organ system. PAX proteins act throughout development and may even contribute to aberrant developmental processes such as cancer; however, the mechanisms of PAX are poorly understood. We seek to understand how PAX functions in unrelated but neighboring cells to synchronize cell fates by utilizing the PAX2/5/8 Caenorhabditis elegans ortholog EGL-38. EGL-38/Pax is necessary for anchoring of the vulva to the uterus in the egg-laying system of C. elegans. This anchoring requires EGF signaling between the epithelial vulva and the mesodermal uterus to specify the cells used as the anchor (uv1 cells). EGL-38/Pax is required for expression of the EGF signal and for uv1 specification. We are examining if EGL-38/Pax directly activates the EGF gene with the help of a co-factor, LIN-1/Ets. Lack of LIN-1/Ets decreases but doesn’t eliminate EGF expression, indicating that it may contribute to but is not the only factor critical for EGF activation. Once activated, EGF signals to specify the uv1 cells. We have discovered that the EGF pathway is necessary for expression of egl-38 in uv1; essentially, EGL-38/Pax in the vulva triggers its own expression in uv1 through the EGF pathway. This is a method of coordinating epithelial and mesodermal cell activity which we are continuing to explore. Additionally, we have shown that EGL-38/Pax is required for expression of a gene in uv1 which may contribute to the biological process of egg-laying. Therefore, the interaction of EGL-38/Pax with the EGF pathway represents a coordination mechanism for the cell fate and biological role of uv1 cells; this interaction motif may also apply to PAX in coordinating organ development in mammals.
Keywords: Organogensis, Coordinated Development, Cell fate