9408718 Abstract This project is a continued exploration of the use of Drosophila in genetic approaches to the nervous system. The analysis is applied to problems in development, including the assembly of the eyes and in the formation of their connections to the brain. Special attention is paid to the role of glial cells in these processes, and in their interaction with neurons in maintenance of the integrity of the brain. Genetic analysis is applied to the mechanism of transmitter release at synapses, characterization of the proteins involved, and the effects on behavior of mutations that alter synaptic proteins. In addition, new molecular genetic techniques are described for isolating mutations in selected genes that are expressed in specific parts of the nervous system, and for generating monoclonal antibodies and associated cDNAs for the corresponding gene products. %%% Given the numerous molecular homologies between the fly and other organisms, including mammals, Drosophila serves as a model system for understanding basic mechanisms in the relation of genes to behavior. ***