Affiliation: | 1. Shirakawa Institute of Animal Genetics, Odakura, Nishigo, Fukushima 961‐8061, Japan;2. Present Addresses: Graduate School of Agriculture, Meiji University, Tama‐ku, Kawasaki, Kanagawa 214‐8571, Japan.;3. Livestock Improvement Association of Japan, Maebashi, Gunma 371‐0121, Japan.;4. Laboratory of Cellular Biology, Graduate School of Agricultural Science, Tohoku University, Aoba‐ku, Sendai, Miyagi 981‐8555, Japan |