1. Hebei University Health Science Center, Baoding, China
2. The Institute for Reproductive Medicine of Hebei University, Baoding, China
3. The Center for Reproductive Medicine of Affiliated Hospital of Hebei University, Baoding, China
4. State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
5. University of Chinese Academy of Sciences, Beijing, China