9307735 Recent theory predicts that some forms of hereditary disease may accumulate in humans and other animals due to opposing selection in the two sexes. Positions on chromosomes (the physical units of hereditary information) where such opposing selection occurs are called sexually antagonistic genes. Males and females of the same species are superficially very similar, yet when examined more carefully they differ in many ways. In a very broad sense, the sexes are designed by natural selection to do different things: males to produce and disseminate microgametes (sperm) and females to produce macrogametes (eggs) and frequently nurture their offspring. The optimal phenotype (i.e. the sum of all characteristics of an organism) for males and females frequently may differ between the sexes leading to adaptation in each sex being compromised via counter selection in the other sex. Recent experiments in my laboratory indicate that sex specific selection leads to a major genetic "tug of war". between the sexes potentially resulting in the build upon of hereditary diseases that produce sex specific dysfunction. %%% The proposed experiments use a Drosophila melanogaster (common fruit fly) model system to confirm and extend these earlier findings. Fruit flies are used because they are so well known genetically and for purely pragmatic reasons (inexpensive culturing, short generation time, etc.). Entire haplotype (one half of the hereditary material carried by an individual) will be transmitted father to son for 50 generations. This protocol eliminates female specific selection. Periodically over the course of the experiment the haplotype will be place in both males and females and each sex's life time fitness will be assayed. If sex specific selection is a major contributor to hereditary disease then these haplotype will substantially increase the fitness in males while reducing the fitness of females.
