COST OF MATING IN DROSOPHILA-MELANOGASTER FEMALES IS MEDIATED BY MALEACCESSORY-GLAND PRODUCTS

FEMALE Drosophila melanogaster with environmentally(1-3) or geneticall y(4) elevated rates of mating die younger than controls. This cost of mating is not attributable to receipt of sperm(5). We demonstrate here that seminal fluid products from the main cells of the male accessory gland are responsible for the cost of mating in females, and that inc reasing exposure to these products increases female death rate. Main-c ell products are also involved in elevating the rate of female egg-lay ing, in reducing female receptivity to further matings and in removing or destroying sperm of previous mates(6-12). The cost of mating to fe males may therefore represent a side-effect of evolutionary conflict b etween males(13).