1. Centre for Hormone Research (W.J.A., S.H.X.A., S.H., G.A.W., V.C.R.), Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville 3052, Victoria, Australia
2. Department of Paediatrics (W.J.A., S.H., G.A.W., V.C.R.), University of Melbourne, Parkville 3010, Victoria, Australia
3. Veterans Affairs Palo Alto Health Care System (J.-F.H., A.R.H.), Stanford University Medical School, Palo Alto, CA 94304
4. Embryology (D.F.N.), Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville 3052, Victoria, Australia