The dorsal thorax of Drosophila is covered with bristles that respond to mechanical stimulation (touch); these sensory organs are part of the adult peripheral nervous system. During third instar larval and early pupal stages, sensory organ precursors (SOPs), each of which gives rise to an individual sensory organ, arise in structures called the imaginal wing discs (larval cells that give rise to the dorsal thorax and the wings of the adult fly). Previous work in Dr. Vaessin's laboratory has shown that the Drosophila gene friend-of-echinoid (fred) has a critical role in limiting the number of SOPs. Remarkably, this requirement for fred gene function is not limited to regions that normally give rise to SOPs, but extends to nearly the entire wing disc. These results reveal an unexpected potential for neural cell formation in most cells of the imaginal wing disc. The focus of the present proposal is to analyze the structure and function of fred and to identify and characterize genes which act downstream of fred in the regulation of sensory organ precursor formation. Drosophila melanogaster is an excellent, well-established model system for the genetic analysis of complex developmental problems. The previous work on fred has established a critical and surprising, yet poorly understood role during early formation of neural and epidermal cells. Thus, the proposed work will provide important new insights into the regulatory network governing neural precursor formation in Drosophila.
Broader Impact: Genes that are critical for normal development are highly conserved between invertebrates and vertebrates. That is, genes involved in a wide range of processes (for example, body pattern formation, organogenesis, and formation of the nervous system) play similar developmental roles in many organisms, including flies and mammals. Therefore, it is expected that the proposed research will also be of direct relevance in understanding similar processes in other organisms. Furthermore, the proposed work provides an important vehicle for the training of graduate and undergraduate students in the molecular genetic analysis of complex developmental problems. In addition, internship opportunities for local High School students will be provided.
