[1] Univ Illinois, Dept Mol & Integrat Physiol, Urbana, IL 61801 USA
[2] Univ Illinois, Dept Cell & Struct Biol, Urbana, IL 61801 USA
[3] Univ Illinois, Dept Vet Med, Urbana, IL 61801 USA
[4] Univ Calif Los Angeles, Harbor Med Ctr, Dept Obstet & Gynecol, Pituitary Hormone Ctr, Torrance, CA 90509 USA