1. Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, P.R. China.
2. Key Laboratory of Embryo Molecular Biology, Ministry of Health and Shanghai Key Laboratory of Embryo and Reproduction Engineering, Shanghai, P.R. China.
3. Laboratory of Developmental Biology, College of Basic Medical Sciences, Shanghai Jiao Tong University, Shanghai, P.R. China.