1. College of Animal Science and Technology, Qingdao Agricultural University Qingdao China
2. Central Laboratory, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing China
3. College of Life Sciences, Institute of Reproductive Sciences, Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, Qingdao Agricultural University Qingdao China
4. Department of Animal Sciences Auburn University Auburn Alabama
5. Reproductive Center, Anqiu Women and Children's Hospital Weifang China