Genome Evolution Laboratory, National Institute of Genetics, Mishima, Japan.|Department of Biological Information, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan.|Department of Biological Information, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan.|Genome Evolution Laboratory, National Institute of Genetics, Mishima, Japan.|Genome Evolution Laboratory, National Institute of Genetics, Mishima, Japan.