Crazy monkey #funny #short

The scientists took advantage of a new technique that allowed them to grow monkey embryos outside the womb for up to 20 days, a stage where the embryos were still largely undeveloped, but had formed layers and cavities. Survival of the embryos declined during the experiment; after 10 days, 103 embryos were still developing, and by day 19, just three of the chimeric embryos remained alive. (After 20 days, monkey embryos grown outside the womb, even those that are not chimeric, simply collapse.)

Still, the researchers found a high number of human cells in the chimeric embryos that survived. On average, 3% to 4% of the cells in the embryos were human, and in one embryo, up to 7% were. “When we observed human cells were alive in monkey embryos, that was amazing,” Tao Tan, a principal investigator at the State Key Laboratory of Primate Biomedical Research and Kunming University of Science and Technology in Yunnan, China, and one of the paper’s lead authors, told STAT.

Work published earlier this year by a research group in France showed that human cells did not survive well in monkey embryos. The key to the success in the new paper may be the particular stem cells that were used, as well as the way they were cultured.

The work, other scientists said, is the most successful to date in keeping a relatively large number of human cells alive and healthy in a nonhuman embryo. “This paper is a dramatic demonstration of the ability of human pluripotent stem cells to be incorporated into the embryos of the cynomolgus monkey,” said Magdalena Zernicka-Goetz, a developmental biologist at Caltech whose lab first developed, in mice, the technique of growing embryos in lab dishes. Such work gained increasing attention with the announcement last month that Jacob Hanna, a developmental biologist at the Weizmann Institute of Science in Israel, had kept mouse embryos alive and seemingly healthy for an extended period in an artificial womb.

The results published Thursday showed a far higher rate of survival for human cells in a nonhuman embryo than in previous experiments with sheep-human or pi