1. Laboratories of Ontogeny and Reproduction (P.R.P., R.D., N.F., Y.T.), Centre Hospitalier Unìversitaire de Québec, Pavillon Centre Hospitalier de l’Université Laval, Québec, Canada G1V 4G2;
2. Department of Obstetrics and Gynecology (C.H.B.), HealthPartners Regions Hospital, St. Paul, Minnesota 55101;
3. Department of Obstetrics and Gynecology and Centre de Recherche en Biologie de la Reproduction (Y.T.), Faculty of Medicine, Laval University, Québec, Canada G1V 4G2