1. Central Laboratory, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital , Beijing 100006 , China
2. School of Medicine, Tsinghua University , Beijing 100084 , China
3. Reproductive Medicine Center, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University , Hefei 230022 , China
4. NHC Key Laboratory of study on abnormal gametes and reproductive tract (Anhui Medical University) , Hefei 230022 , China
5. Tsinghua-Peking Center for Life Sciences, Tsinghua University , Beijing 100084 , China
6. Zhili College, Tsinghua University , Beijing 100084 , China
7. School of Life Sciences, Tsinghua University , Beijing 100084 , China