1. Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
2. Faculty of Agriculture, Shinshu University, Nagano 399-4598, Japan
3. Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan and
4. UMR INRA/INA-PG Génétique et Diversité Animales, 78352 Jouy-en-Josas, France