1. Laboratory of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi 753-8515, Japan
2. Department of Veterinary Anatomy, School of Veterinary Medicine, Tottori University, Tottori 680-8553, Japan
3. Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA
4. Department of Computational & Systems Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15260, USA