1. Department of Cell Biology (C.J.B., C.E.P., H.M., K.E.K.), Cincinnati, Ohio 45267-0521;
2. Laboratories of Reproductive Biology (E.M.W.) and the Department of Pediatrics and Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7500
3. Center for Environmental Genetics (K.E.K.), University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0521;