In both vertebrates and Drosophila suggest that similar positional cues regulate dorsal ventral patterning within the CNS. During formation of the Drosophila CNS NB's form in three rows parallel to the ventral midline. Initially the ventral and dorsal columns form, followed by filling in of the intermediate column. ventral nervous system defective (vnd) is expressed in the ventral NB column, and muscle segment homeobox (msh) is expressed in the lateral column. While vnd plays a key role in formation of the medial column NBs and msh plays a similar role in the lateral column it remains unclear if there is a similar factor regulating formation of the intermediate column NBs. This project focuses on defining a role for a newly discovered gene, intermediate neuroblasts defective (ind). indis a novel homeodomain protein expressed in the intermediate column. Characterization of ind will include determination of the loss and gain of function phenotypes and identification of downstream targets. In parallel I will test two putative murine homologs (Gsh 1 and Gsh 2) for functional conservation.