1. Department of Biomedical Science and Technology, Konkuk University, Seoul 143-701, Korea
2. Institute of Biomedical Science and Technology, Konkuk University, Seoul 143-701, Korea
3. Department of Anatomy, School of Medicine, Konkuk University, Seoul 143-701, Korea
4. ToolGen, Inc., Biotechnology Incubating Center, Seoul National University, Seoul 305-390, Korea
5. College of Veterinary Medicine, Konkuk University, Seoul 143-701, Korea