Maternal Control of Epithelial Motility in the C. Elegans Embryo

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

0112803 Hardin As the fertilized egg develops into an embryo, its shape changes dramatically as it gradually transforms into a recognizable animal, a process known as morphogenesis. Two of the major cellular movements that shape animal embryos are rearrangement of cells in a preferred direction, and spreading of cell sheets. Both processes require parts of moving cells to extend in very specific directions. The Hardin laboratory will investigate directed movements of cell sheets, using the embryonic epidermis of the nematode, C. elegans, as a model system. They seek to answer the following questions: (1) What events during epidermal morphogenesis are regulated by the dishevelled family member DSH-2? DSH-2 is required for cell rearrangement in the dorsal hypodermis, and for the subsequent epiboly event known as ventral enclosure. They will analyze the defects in dsh-2 embryos dynamically, using computer-assisted microscopy, analysis of fluorescent proteins in living embryos using the green fluorescent protein, and markers for the cytoskeleton and differentiation. (2) What cells require DSH-2 function for epidermal morphogenesis? They will determine the localization of DSH-2 during morphogenesis, and drive DSH-2 expression in specific tissues. (3) What molecular pathways require DSH-2 during epithelial morphogenesis? They will use deletion constructs to identify which parts of DSH-2 are required for epidermal morphogenesis. They will also investigate the relationship between the maternally acting Frizzled MOM-5, other candidate Wnt/Frizzled molecules, and DSH-2. (4) What other genes act maternally to regulate epidermal morphogenesis in C. elegans? The Hardin laboratory has conducted an extensive pilot screen for additional genes that act in early steps of epidermal morphogenesis. They will analyze candidate mutants, using standard techniques. As a result of these studies, the Hardin laboratory will gain fundamental insights into regulation of polarized movement of epithelial sheets, a process that is fundamental to many processes in embryonic development.