Our intellectual focus is on identifying determinants of cell shape that function during development. Utilizing molecular genetic and reverse genetic approaches in Drosophila, we have shown that conventional nonmuscle myosin is necessary for driving both cell division and post-mitotic cell shape changes for morphogenesis, and cellular locomotions. Currently, we are investigating how myosin elicits cell shape change and how its function is regulated through filament formation, phosphorylation, sub-cellular targeting and small GTP-binding protein function. We are characterizing myosin light chain kinase; a novel myosin VII heavy chain; and additional elements that participate in localizing myosin and transmitting the forces that it produces. We used screens for aberrant cell shape induced in the yeast S. pombe by expression of transfected Drosophila cDNAs. These experiments show that elements that define cell shape are conserved throughout phylogeny and that a screen in yeast is a valuable tool for recovering heterologous cDNAs that encode cytoskeletal elements and the proteins that regulate them. In fly, we are identifying gene products that are necessary for myosin function by genetically recovering second site non-complementing loci and biochemically recovering proteins that bind to myosin. To date, our experiments identify ~30 loci that genetically interact with myosin and a kinase activity that phosphorylates myosin heavy chain and establish genetically, that the Rho signalling pathway is required in concert with nonmuscle myosin II for morphogenesis. We are also using manipulation studies to understand the forces that drive cellularization and morphogenesis. We show that both the amnioserosa and the leading edge of the lateral epidermis contribute to the movements of dorsal closure. Finally, we are examining the role these proteins play in movements that occur during wound healing.

Education

• Ph.D., University of Pennsylvania 1979

• B.A., University of Pennsylvania 1973