While all cells ultimately die, very little is known about the molecular mechanisms which bring about this developmental phenomenon. One very attractive model system for study, is the intersegmental muscles (ISM) of the moth Manduca sexta, which die during the 36 hours following adult emergence. The commitment of the ISM to degenerate involves the activation of a new set of cell death genes, five of which have been cloned in my lab. The experiments outlined in this proposal will provide insight into the identity and function of these genes in both insects and vertebrates. A range of molecular approaches will be used to isolate, sequenced and express cell death genes. Additionally, culture cells and insect muscle fibers will be injected or transfected with one of the following molecules generated from our clones: anti-sense transcripts, sense transcripts, antibodies, purified expressed proteins or recombinants made with a reporter gene fused to putative cell-death gene promotors. These experiments should greatly increase our understanding of the molecules which are used by cells to die during development and aging. I am currently an assistant professor of Zoology, with a background in physiology, membrane biophysics and recently, molecular biology. My teaching and administrative commitments are quite demanding, which limits my ability to both learn new techniques and visit other labs for training. The time made available by an RCDA will dramatically increase my ability to exploit this powerful cell death model system. It is clear that examination of such model systems will provide basic insight into the molecular mechanisms which mediate senescence and death in animal cells.