The researchers injected 25 cells known as induced pluripotent stem cells from humans — commonly called iPS cells — into embryos from macaque monkeys, which are much more closely genetically related to humans than are sheep and pigs.
After one day, the researchers reported, they were able to detect human cells growing in 132 of the embryos and were able study the embryos for up to 19 days. That enabled the scientists to learn more about how animal cells and human cells communicate, an important step toward eventually helping researchers find new ways to grow organs for transplantation in other animals, Belmonte said.
“This knowledge will allow us to go back now and try to re-engineer these pathways that are successful for allowing appropriate development of human cells in these other animals,” Belmonte told NPR. “We are very, very excited.”
Such mixed-species embryos are known as chimeras, named for the fire-breathing creature from Greek mythology that is part lion, part goat and part snake.
“Our goal is not to generate any new organism, any monster,” Belmonte said. “And we are not doing anything like that. We are trying to understand how cells from different organisms communicate with one another.”
https://wbhm.org/npr_story_post/2021/scientists-create-early-embryos-that-are-part-human-part-monkey/