1. Medical Research Council Human Reproductive Sciences Unit (R.P.M., Z.-L.L., A.J.P., K.M., S.R.M.), Centre for Reproductive Biology, Edinburgh EH16 4SB, Scotland, United Kingdom
2. Division of Medical Biochemistry and Department of Medicine (R.P.M., C.A.F.), University of Cape Town Faculty of Health Sciences, Cape Town 7925, South Africa