In Drosophila, neural precursor genes are expressed in neural progenitor cells as the neuroblasts and sense organ mother cells. These genes are thought to control the fate and/or behavior of neural progenitor cells once their fate decision has been made. We have isolated and characterized a novel neural precursor gene, inscuteable, whose expression is coincident with sites of cell shape changes or cell and tissue movement in the embryo, e.g., neuroblasts, trachea, Malphigian tubules, and in pupal wing epithelia. The Inscuteable protein is localized to the apical submembranous surface of neuroblasts and other cell types and shows certain features common to a family of putative cytoskeletal associated proteins. The inscuteable mutant phenotype, together with these other observations, suggests a possible role for the protein in cytoskeleton organization.