1. Laboratory of Basic Veterinary Science, United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi 753-8515, Japan
2. Department of Anatomy and Embryology, Faculty of Veterinary Medicine, South Valley University, Qena 83523, Egypt
3. Department of Anatomy and Physiology, University of Pretoria, Onderstepoort 0110, South Africa
4. Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan