Second Chinese Group Produce Mice from iPS Cells

Second Chinese Group Produce Mice from iPS Cells Thursday, 23 July 2009 Two teams of Chinese researchers have created live mice from induced pluripotent stem (iPS) cells, answering a lingering question about the developmental potential of the cells. Animal cloners Qi Zhou of the Institute of Zoology in Beijing and Fanyi Zeng of Shanghai Jiao Tong University started by creating iPS cells the same way as Shinya Yamanaka of Kyoto University in Japan, by using viral vectors to introduce four genes into mouse fibroblast cells. The Chinese team tried hard, tweaking the culture medium and analysing 250 developing embryos before getting their first mouse. In the paper, the team reports 27 live births. With their best cell line and optimal recipe, they were able to get 22 live births from 624 injected embryos, a success rate of 3.5%. Some of their mice passed one of the most fundamental tests of health: all 12 mice that were mated produced offspring, and the offspring showed no abnormalities. The team says it now has hundreds of second-generation, and more than 100 third-generation, mice. The team found no tumours in the mice, although they have not systematically looked for them. The leader of the other team, Shaorong Gao of the National Institute of Biological Sciences in Beijing, also credits persistence for success. His group, which used the same basic technique as Zeng and Zhou, transferred iPS cells to 187 tetraploid complementation embryos to get just two live births (a 1.1% efficiency rate), although one died in infancy. "The chance for generating such a cell line is rare but we tried very hard," he says. Gao's team is now trying to mate its surviving mouse. Reference: iPS cells produce viable mice through tetraploid complementation Xiao-yang Zhao, Wei Li, Zhuo Lu, Lei Liu, Man Tong, Tang Hai, Jie Hao, Chang-long Guo, Qing-wen Ma, Liu Wang, Fanyi Zeng & Qi Zhou Nature advance online publication 23 July 2009, doi:10.1038/nature08267 See also: Mice made from induced stem cells David Cyranoski Nature News, Published online 23 July 2009, doi:10.1038/460560a Mice Grown from iPS Cells by Chinese Researchers Reprogrammed mouse fibroblasts can make a whole mouse CellNEWS - Thursday, 23 July 2009 ......... ZenMaster

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