1. Academy of Animal and Veterinary Science, Qinghai University, Xining, People's Republic of China
2. Gansu Key Laboratory of Herbivorous Animal Biotechnology, College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, People's Republic of China
3. Gene-Marker Laboratory, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, New Zealand
4. Program in Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada