1. Graduate School of Frontier Biosciences, Osaka University, Yamadaoka 1-3, Suita, Osaka 565-0871, Japan
2. Department of Developmental Biology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
3. Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555, Japan
4. Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA
5. Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan