February 6 2006
9:30 LSB 2320

Abstract:

I am interested in the cellular interactions that drive the morphogenesis of tissues and organs. My laboratory has studied development of the C. elegans epidermis as a model. We use a combination of forward genetics, biochemistry and timelapse video analysis to dissect signaling and cytoskeletal pathways involved. Epidermal cells spread over substrate neuroblasts in the classic movement of epiboly. We find that ephrin signaling acts within neuroblast substrate cells to coordinate their movements. Ephrins have both repellent and adhesive functions in development; our work suggests that in C. elegans ephrins act to promote adhesion among neuroblasts. Several other adhesive pathways operate in neuroblast movement, including the LAR-like receptor tyrosine phosphatase and the Kallmann syndrome protein. In later development the epidermis undergoes cell shape changes that result in fourfold elongation of the body. We have identified functions for extracellular matrix proteins in this process, including F-spondin and Peroxidasin. We have recently begun an investigation of post-embryonic epidermal development, focusing on a kinase that may control autophagy within the epidermis.