RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan Reifycs Incorporated, 1-6-12 Nishishinbashi, Minato-ku, Tokyo 105-0003, Japan and National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.