1. Department of Biology, Graduate School of Science Kobe University 1‐1 Rokkodai, Nada‐ku Kobe Hyogo 657‐8501 Japan
2. The Institute for Advanced Research Kobe University 1‐1 Rokkodai, Nada‐ku Kobe Hyogo 657‐8501 Japan
3. Graduate School of Agricultural and Life Sciences The University of Tokyo 1‐1‐1, Yayoi Bunkyo‐ku Tokyo 113‐8657 Japan
4. Radioisotope Research Center Nagoya University Furo‐cho, Chikusa‐ku Nagoya Aichi 464‐8602 Japan
5. Department of Biology, Graduate School of Science Osaka Metropolitan University 1‐1 Gakuen‐cho, Naka‐ku Sakai Osaka 599‐8531 Japan
6. Department of Chemical and Biological Sciences, Faculty of Science Japan Women's University Bunkyo‐ku Tokyo 112‐8681 Japan