Willis, Joel P.

Several models for the evolution of maternal inheritance of mitochondria predict that the sperm mitochondria undergo oxidative damage and pose a threat to the developing embryo. Here, I test the hypothesis that the sperm are damaged by reactive oxygen species generated by aerobic sperm activity. In my first experiment, I found no significant difference in fecundity between worms fertilized by old versus young sperm, suggesting that the sperm nuclear genome is not affected by the extent of sperm activity. In my second experiment, I found that sperm mitochondrial DNA has deletions, indicating damage, but this damage does not accumulate with sperm activity. However, problems with PCR amplification resulted in little experimental data, preventing a conclusive test of the hypothesis.