1. Laboratory for Pluripotent Stem Cell Studies, RIKEN Center for Developmental Biology (CDB), Minatojima-minamimachi 2-2-3, Chuo-Ku, Kobe 650-0047, Japan
2. CREST (Core Research for Evolutional Science and Technology), Japan Science Technology Agency, Honcho 4-1-8, Kawaguchi, Saitama 332-0012, Japan
3. Laboratory for Development and Regenerative Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunokicho, Chuo-ku, Kobe 6500017, Japan