Two piglets recently born in China look like average swine on the outside, but on the inside, they are (a very small) part monkey.
A team of researchers generated the pig-primate creatures by injecting monkey stem cells into fertilized pig embryos and then implanting them into surrogate sows, according to a piece by New Scientist. Two of the resulting piglets developed into interspecies animals known as chimeras, meaning that they contained DNA from two distinct individuals — in this case, a pig and a monkey.
“This is the first report of full-term pig-monkey chimeras,” co-author Tang Hai, a researcher at the State Key Laboratory of Stem Cell and Reproductive Biology in Beijing, told New Scientist. Eventually, Hai and his colleagues aim to grow human organs in animals for use in transplant procedures. For now, the team plans to stick with monkey cells, as developing human-animal chimeras presents a slew of “ethical issues,” the authors noted in a report published Nov. 28 in the journal Protein & Cell.