1. Medical Research Council Human Reproductive Sciences Unit (K.M., A.J.P., R.S., T.R.O., R.P.M.), University of Edinburgh Academic Centre, Edinburgh EH16 4SB, United Kingdom;
2. ZymoGenetics Inc. (D.C.), Seattle, Washington 98102;
3. Medical Research Council Molecular Reproductive Endocrinology Unit (R.P.M.), University of Cape Town Medical School, Observatory 7925, Cape Town, South Africa