1. Division of Reproductive Biology, Department of Obstetrics and Gynecology (S.M., S.S., C.A.K., J.V.Z, K.K., A.J.W.H.), Stanford, California 94305
2. Departments of Comparative Medicine (D.M.B.), Stanford, California 94305
3. Biology (L.V.G, H.R., M.T.-L.), Stanford University, Stanford, California 94305