The aim of this research is to deduce how the genome specifies neuronal connections by focussing on mutation that alter a particular identifiable synapse in the adult Drosophila nervous system. The synapse is part of the giant fiber escape system; it connects the giant fiber interneuron and the jump muscle motoneuron. Mutations which alter the structure and/or function of the giant fiber-jump muscle motoneuron connection may be identified by a combination of behavioral, electrophysiological, and neuroanatomical methods. One such mutation defines the bendless (ben) gene which appears to play a key role late in the formation of neuronal connections. It may be involved in the final recognition events between a presynaptic neuron and its post-synaptic target. Dr. Tanouye will conduct a detailed genetic and phenotypic analysis of ben to determine the nature of its role in neuronal connectivity. He will then clone the ben gene, determine if its product has amino acid homology to other known molecules, and study the spatial and temporal pattern of its expression. The detailed genetic and molecular description of how one particular synapse is formed may serve as a model that gives insight into the general problem of neuronal connectivity.
