1. Center for Research on Reproduction and Women’s Health, University of Pennsylvania (L.K.C., J.F.S.), Philadelphia, Pennsylvania 19104;
2. Department of Molecular Biology and Biochemistry, University of California (T.F.O.), Irvine, California 92717;
3. Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine (J.M.M.), Hershey, Pennsylvania 17033