Scientists Grow Monkey Chimera With Human Cells

KUNMING, CHINA — A team of U.S. and Chinese scientists has successfully implanted human cells into monkey embryos, according to a study published in the journal Cell on April 15.

According to the research, the process began with the reprogramming of mature skin or blood cells into a stem-cell-like state. Stem cells are the cells from which all other cells with more specialized functions develop.

Citing the study, Science Alert reports that 25 of these reprogrammed human cells were added to macaque monkey embryos to form what is known as a chimera, or mixed-species embryo.

Speaking to the Guardian, research co-author Jun Wu, an assistant professor in the Department of Molecular Biology at the University of Texas Southwestern Medical Center, said human cells made up around four percent of the chimera embryos.

Science Alert notes that 132 of the chimera embryos formed initially. After 10 days, 103 of the chimeric embryos were still alive and developing. By day 19, only three chimeras remained alive, and on day 20 all of the hybrid embryos had been destroyed for ethical reasons.

In their study, the researchers note they consulted with bioethicists and thus grew the embryos in a lab rather than a surrogate. This is also why they did not allow the chimera to develop beyond the 20-day mark.