1. Yoshizato Project, Cooperative Link of Unique Science and Technology for Economy Revitalization (CLUSTER), Hiroshima Prefectural Institute of Industrial Science and Technology, Higashihiroshima, Hiroshima 739-0046, Japan.
2. Division of Frontier Medical Science, Department of Surgery, and Hiroshima University 21st Century COE Program for Advanced Radiation Casualty Medicine, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan.
3. Hiroshima Tissue Regeneration Project, Collaboration of Regional Entities for the Advancement of Technological Excellence (CREATE), Japan Science Technology Agency, Hiroshima Prefectural Institute of Industrial Science and Technology, Higashihiroshima, Hiroshima 739-0046, Japan.
4. Hiroshima University Liver Project Research Center, Hiroshima 734-8551, Japan.
5. Present address: Tokyo Medical and Dental University, Tokyo 113-8510, Japan.
6. Developmental Biology Laboratory and Hiroshima University 21st Century COE Program for Advanced Radiation Casualty Medicine, Department of Biological Science, Graduate School of Science, Hiroshima University, Higashihiroshima, Hiroshima 739-8526, Japan.