1 State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chaoyang District, Beijing, China; Institute for Stem Cell and Regeneration, Chaoyang District, Beijing, China; University of Chinese Academy of Sciences, Chaoyang District, Beijing, China.
2 State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chaoyang District, Beijing, China; Institute for Stem Cell and Regeneration, Chaoyang District, Beijing, China; University of Chinese Academy of Sciences, Chaoyang District, Beijing, China. Electronic address: huangsq@ioz.ac.cn.