1. Department of Biological Sciences (J.L.K., A.G., G.R., M.D.), DePaul University, Chicago, Illinois 60614
2. Departments of Molecular Biosciences (S.M.K., K.E.M.), Northwestern University, Evanston, Illinois 60208
3. Center for Reproductive Science (S.M.K., K.E.M.), Northwestern University, Evanston, Illinois 60208
4. Neurobiology and Physiology (K.E.M.), Northwestern University, Evanston, Illinois 60208