1. Institute of Molecular Embryology and Genetics (S.M., K.S., G.Y.), Kumamoto 860-0811, Japan
2. Center for Animal Resources and Development (S.M., Y.S., R.H., K.S., N.N., G.Y.), and Global Center of Excellence Cell Fate Regulation Research and Education Unit, Kumamoto University, Kumamoto 860-0811, Japan
3. Okazaki Institute for Integrative Bioscience (I.T.), National Institutes of Natural Sciences, Okazaki 444-8787, Japan
4. Graduate School of Medicine (M.M.T), Kyoto University, Kyoto 606-8501, Japan
5. Institute of Molecular and Cellular Biosciences (T.M., K.T., S.K), University of Tokyo and Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Tokyo 113-0032, Japan