1. Department of Biological Science, College of Natural Sciences, Wonkwang University, Iksan 570-749, Korea.
2. Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Muenster 48149, Germany.
3. The Institute of Molecular Medicine and Genomics and Department of Neurology, Medical College of Georgia, Augusta, GA 30912, USA.
4. National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Ochang 363-883, Korea.