1. Department of Virology, Institute of Medical Science, University of Tokyo 4‐6‐1 Shirokanedai, Minato‐ku Tokyo 108‐8639 Japan
2. Human Genome Center, Institute of Medical Science, University of Tokyo 4‐6‐1 Shirokanedai, Minato‐ku Tokyo 108‐8639 Japan
3. Genome Science Center, Institute of Physical and Chemical Research (RIKEN) 2‐1 Hirosawa, Wakoshi Saitama 351‐0106 Japan
4. Intelligent Communication Laboratory, NTT Communication Science Laboratories 2‐4 Hikaridai, Seika‐cho, Soraku‐gun Kyoto 619‐0237 Japan
5. Department of Complexity Science and Engineering Graduate School of Frontier Science, University of Tokyo 7‐3‐1 Hongo, Bunkyo‐ku Tokyo 113‐0033 Japan
6. Helix Research Institute 3‐1532 Yana, Kisarazushi Chiba 292‐0812 Japan
7. Institute of Molecular and Cell Biology, University of Osaka 1‐3 Yamadaoka, Suita‐shi Osaka 565‐0871 Japan
8. Department of Life Sciences, University of Tokyo 3‐8‐1 Komaba, Meguro‐ku Tokyo 153‐0041 Japan