1. Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, Korea.
2. Department of Cell and Developmental Biology, University College London, London, United Kingdom.
3. Division of Animal Science, Faculty of Agriculture, Shinshu University, Nagano, Japan.
4. Institute for Biomedical Sciences, Shinshu University, Nagano, Japan.