1. Department of Cell Biology, Institute for Molecular and Cellular Regulation, Gunma University
2. Department of Histology, The Nippon Dental University School of Dentistry at Tokyo
3. Pharmaceutical Research Laboratory, Kirin Brewery Co., Ltd.
4. Institute of Applied Biochemistry, University of Tsukuba
5. Present address: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University
6. Institute of Basic Medical Sciences, University of Tsukuba
7. Present address: Department of Anatomy, Osaka University Medical School
8. Gene Experiment Center, University of Tsukuba