1. College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling Shaanxi, China
2. Institute of Reproductive Sciences, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
3. Department of Reproductive Medicine, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, China