1. Medical Research Council Human Reproductive Sciences Unit, University of Edinburgh Center for Reproductive Biology (J.R.M., P.T.K.S., A.S.M.), Edinburgh, Scotland EH3 9ET;
2. Medical Research Council Human Genetics Unit, Western General Hospital (M.T., H.J.C.), Edinburgh, Scotland EH4 2XU;
3. Center for Proteins and Peptides, School of Biological and Molecular Sciences, Oxford Brookes University (M.C.), Headington, Oxford, United Kingdom OX3 0BP