1 College of Life Sciences, Key Laboratory of Animal Reproduction and Biotechnology in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China.
2 Department of Animal Sciences, Auburn University, Auburn, AL, 36849, USA.
3 Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133, Rome, Italy.
4 College of Life Sciences, Key Laboratory of Animal Reproduction and Biotechnology in Universities of Shandong, Qingdao Agricultural University, Qingdao, 266109, China. wshen@qau.edu.cn.