1. Laboratory of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
2. Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
3. Laboratory of Theriogenology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
4. Laboratory of Molecular and Cellular Physiology, Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8526, Japan
5. Laboratory of Veterinary Anatomy, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
6. Faculty of Health Science, Butsuryo College of Osaka, Osaka 593-8328, Japan