9410212 Ellis Development of multicellular organisms requires individual cells, or groups of cells, to adopt fates that differ from their neighbors. These highly reproducible cell fate decisions must be executed in a spatially and temporally specific manner. The goal of this work is to understand, at a molecular and cellular level, how cell fate decisions are regulated during development. Several consistent themes emerge from the study of cell fate decisions in both vertebrates and invertebrates: Cell fates are often arrived at by a process of gradual or sequential restriction of developmental potential. This restriction of potential is due to specific gene expression or activity. Cell-cell communication is a critical component of developmental decisions in all organisms in which the process can be studied. Finally, proteins identified by genetic analysis of simple organisms as being critical for specific events in development often play similar roles in higher organisms. Development of insect sensory organs requires that cells make a spatially specific choice between two alternative fates, epidermoblast or sensory organ precursor. This study will use genetic, cellular and molecular approaches to determine the role of a specific gene in this cell fate choice. In mutants lacking normal gene function, inappropriate cell fate choices are made resulting in the presence of extra sensory organs. Thus, this gene must be an important component of the mechanisms that regulate formation of sensory organ precursors. This work will provide fundamental information about gene regulation and cell-cell communication.
