David S. Stein

Research in our lab is focused mainly on the question of how a complex multicellular organism develops from a single cell, the fertilized Drosophila egg. Specifically, we are studying how Drosophila embryonic dorsal-ventral and anterior-posterior polarity is established. The embryonic dorsal-ventral axis is defined by a ventrally-produced extracellular ligand which binds to and activates Toll, a receptor protein present throughout the membrane of the early embryo. Similarly, formation of the anterior and posterior termini of the Drosophila embryo is controlled by an extracellular ligand that activates another uniformly distributed receptor protein, Torso, specifically at the two ends of the embryo. Experiments in our lab are aimed at understanding at the molecular level how spatially-restricted activation of these two receptors is accomplished and defines embryonic pattern along the dorsal-ventral axis and at the embryonic termini. Finally, we are interested in the development of new experimental technologies that can be applied to the analysis of biological questions. In this context, a third project in the lab has to goal of developing an experimental optogenetic strategy that will permit light-induced elimination of protein function for phenotypic analysis in vivo.