1. Department of Physiology, Department of Dentistry and Oral Surgery, Department of Cell Differentiation, the Sakaguchi Laboratory of Developmental Biology, Department of Orthopedic Surgery and Department of Ophthalmology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
2. Laboratory for Cell Function and Dynamics, Advanced Technology Development Group, Brain Science Institute, Institute of Physical and Chemical Research, Wako-city, Saitama 351-0198, Japan
3. Life Function and Dynamics, Exploratory Research for Advanced Technology Office, Japan Science and Technology Agency, Wako-city, Saitama 351-0198, Japan