A chimera human-monkey blastocyst. Weizhi Ji, Kunming University of Science and Technology
Scientists injected human stem cells into macaque embryos into a study on human development.
Some of the embryos continued to develop for 20 days, researchers said.
But the experiment has sparked an ethical debate among scientists.
Monkey embryos containing human cells were kept alive for 20 days in an experiment carried out by a US-Chinese team.
The embryos were made by injecting human stem cells into macaque embryos as part of research into early human development, and results were published in the journal “Cell.” Only some of the embryos survived for 20 days, the research said.
The research team was led by Juan Carlos Izpisua Belmonte of the Salk Institute, who helped make