Cell death is a fundamental process in animal development and homeostasis, and mis-regulation of cell death is associated with a large number of human diseases including cancer and neurodegenerative disorders. While much is known about mechanisms of apoptotic cell death, far less is known about non-apoptotic forms of cell death which contribute significantly to development and disease. Our research focuses on uncovering the mechanisms that control a non-apoptotic form of cell death that occurs naturally in the Drosophila ovary, a model system with powerful tools in genetics and cell biology. During late stages of oogenesis, germline- derived nurse cells undergo synchronous programmed cell death. In the prior grant periods, we determined that developmental nurse cell death can occur independently of apoptosis and autophagy genes, and nurse cell death displays hallmarks of necrosis. We recently discovered a transcription factor that inhibits nurse cell death more strongly that combined inhibition of apoptosis and autophagy. Furthermore, we have found that follicle cells, which surround the nurse cells, act non-cell-autonomously to promote nurse cell removal. We propose that nurse cell death involves collaboration between novel pathways acting autonomously in the germline and non-autonomously in the surrounding somatic follicle cells. This proposal aims to uncover the network acting in the nurse cells and follicle cells that culminates in nurse cell death. First, we will investigate the events occurring in follicle cells, nd how these coordinate with nurse cell death. Second, we will characterize the targets of transcription factors found to direct the cell- autonomous cell death pathway in nurse cells. Third, we will determine how the upstream activators of nurse cell death control specific nuclear events and interface with downstream effectors. Given the high degree of conservation of cell death mechanisms between Drosophila and mammals identified thus far, we expect that pathways that we uncover in the fly ovary will provide insight into the diversity of cell death mechanisms in humans. A complete understanding of the mechanisms controlling cell death may reveal new therapeutic targets for diseases with excessive or insufficient cell death such as neurodegenerative disorders and cancer.