1. Japan Tobacco Inc., Central Pharmaceutical Research Institute, 1–1 Murasaki-cho, Takatsuki, Osaka 569-1125, Japan
2. Laboratory of Animal Genetics, Graduate School of Science and Technology, Niigata University, Nishi-ku, Niigata 950-2181, Japan
3. CLEA Japan Inc., Planning and Development Section, 1–2–7 Higashiyama, Meguro-ku, Tokyo 153-8533, Japan