1. School of Basic Medical Sciences (G.S.), Wuhan University, Wuhan 430072, Peoples Republic of China
2. Section on Molecular Morphogenesis (G.S., R.A.H., L.F., B.D., Y.-B.S.), Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
3. Department of Biology (T.H., A.I.-O.), Nippon Medical School, Kawasaki, Kanagawa 211-0063, Japan