In this proposal I will use the CMS midline cells to study the genetic basis of neurogenesis and the generation of neural cell type diversity. The development of the Drosophila CMS midline cells illustrates a large number of key developmental processes including cell-cycle control, cell-cell signaling, cell migration, and apoptosis. Together with the genetic and genomic resources available to the Drosophila community, the ease of identifying genes expressed in these cells, and their location along the ventral midline the Drosophila CMS midline cells have the potential to be an excellent developmental and genomic model system. This proposal is designed to generate a detailed map of midline cell gene expression, fate, and cellular dynamics such that each midline cell and its progenitors can be identified. I will use this information to isolate and characterize the functional role of transcription factors that promote cell fate and differentiation in midline neurons. Through the combination of descriptive and functional-genetic studies I will begin to dissect the molecular and genetic pathways that control the development and differentiation midline neurons.