1. Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
2. Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0075, Japan
3. Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
4. Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
5. Agency for Medical Research and Development-Core Research for Evolutional Medical Science and Technology (AMED-CREST), Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-1004, Japan