1. Laboratory of Animal Reproduction, Faculty of Agriculture, Kagoshima University, Kagoshima 890-0065, Japan
2. School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
3. BioVerde Incorporated, Kyoto 601-8023, Japan
4. Section of Swine, Kagoshima Prefectural Economics Federation of Agricultural Cooperatives, Kagoshima 890-8515, Japan
5. Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima 890-0065, Japan