1. ¹Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
2. ²Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Correspondence: Dayuan Chen, chendy@ioz.ac.cn; Hui Z Sheng, hzsheng2003@yahoo.com

^*These two authors contributed equally to this work.

Hui Z Sheng, MD/PhD, MD from Shanghai Second Medical University. PhD from La Trobe University, Victoria, Australia. Worked on mammalian development in National Institutes of Child Health and Human Development (NIH, USA). Returned to Shanghai, China in 1999 to become head, Center for Developmental Biology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine (recently retired). Major research interests: human embryonic stem cells, nuclear transfer embryonic stem cells, and mechanism of nuclear reprogramming. Major publications: Embryonic stem cells generated by nuclear transfer of human somatic nuclei into rabbit oocytes Cell Res (2003); 13(4):251-264; Nuclear reprogramming: the zygotic transcription program is established through an "erase-and-rebuild" strategy. Cell Res 2007;17(2):117-134. Nuclear reprogramming: the strategy used in normal development is also used in somatic cell nuclear transfer and parthenogenesis. Cell Res 2007;17(2):135-150.