Regulatory information is passed from one cell or tissue type to another during the development of multicellular organisms. Development of the nematode, Caenorhabditis elegans, has been described in detail at the cellular level and includes several instances where regulatory cell-cell interactions decide cell fate. This proposal investigates the mechanisms underlying two such regulatory interactions: induction of mitosis in the germ line and induction of pharyngeal muscle cells in the early embryo. These two events occur at different times and in different tissues but share a common component: the glp-1 gene. Extensive genetic and molecular studies suggest that glp-1 acts as a signal receptor in each of the induced tissues. Dr. Maine has generated extragenic suppressors of glp-1 mutations as a way of identifying genes responsible for signal production in the inducing tissue and signal transduction in the induced tissue. This proposal outlines genetic and molecular studies and cell ablation experiments that are designed to analyze the role(s) of these newly identified genes in the germ line and embryonic cell- cell interactions. In particular, the proposal focuses on one gene identified as a recessive suppressors, sog-1, and on a set of dominant suppressors that are linked to glp-1. %%% The proposed studies are designed to investigate how cell fate is specified during the development of multicellular organisms. In particular, the experiments will focus on the cell-cell interactions that are reguired to specify the fates of individual cells as they differentiate into one or another adult cell type.
