IBN 9601282 PI: Jocelyn Shaw The long-term objectives of this research are to understand aspects of neuronal structure and function in a model animal as part of an overall goal of understanding how a complete nervous system is formed and functions. The unc-7 gene is required in the nervous system for properly coordinated movement in the nematode worm and is the focus of these investigations. unc-7 appears to affect several properties of neurons including the specificity with which they make electrical connections to other neurons. unc-7 is related to other genes in C. elegans, which are postulated to be required for communication between cells via small channels (gap junctions). The function of unc-7 will be investigated by analyzing in more detail which cells in the animal express unc-7, the location within these cells of the UNC-7 protein, and the manner in which loss of unc-7 function affects neuronal development and function in the animal. Genes that may interact with unc-7 or modulate unc-7 function will be identified genetically, a powerful technique well-suited to C. elegans. Identification of such genes will broaden our understanding of how unc-7 functions. The hypothesis that unc-7 and related genes encode the protein components of gap junction channels will be tested by examining the effect that these proteins have on gap junctional connections between cells. UNC- 7 and a related protein will be expressed in cells that do not normally form gap junction channels to see whether channels are now formed between cells. They will also be expressed in cultured insect cells to see whether the properties of the gap junction channels formed between these cells are altered.