ACTIVATION OF THE REAPER GENE DURING ECTOPIC CELL-KILLING IN DROSOPHILA

The product of the reaper (rpr) gene is required for programmed cell d eath in Drosophila. We examined rpr expression during ectopic cell dea ths caused by ionizing radiation or aberrant development. In both inst ances, dramatic induction of rpr expression was observed. A genomic fr agment upstream of rpr confers this regulatory behavior upon a lacZ re porter transgene. In a model cell culture system, conditional expressi on of REAPER is sufficient to induce massive apoptosis that can be pre vented by the anti-apoptotic protein p35. Overall, these results sugge st that diverse signals converge at, or upstream of, rpr-associated tr anscriptional regulatory elements that can function to initiate a comm on apoptotic pathway involving ICE-like protease activity. (C) 1996 Ac ademic Press, Inc.