1. Neuroscience Graduate Program (Y.K.), The University of Michigan, Ann Arbor, Michigan 48109-1048
2. The University of Michigan, Ann Arbor, Michigan 48109-1048; UMR-7221, Centre National de la Recherche Scientifique (L.M.S., P.B.), The University of Michigan, Ann Arbor, Michigan 48109-1048
3. Muséum National d’Histoire Naturelle, 75005 Paris, France; and Department of Molecular, Cellular, and Developmental Biology (L.W., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109-1048