Using CRISPR, the scientists spliced genes for the mammoths’ small ears, subcutaneous fat, and hair length and color into the DNA of elephant skin cells. The tissue cultures represent the first time woolly mammoth genes have been functional since the species went extinct around 4,000 years ago.
Just making a DNA change isn’t that meaningful,” says Church. “We want to read out the phenotypes.” To do that, the team needs to figure out how to take the flat hybrid cells from a petri dish and coax them into becoming specialized tissues–such as blood cells or liver organoids–then test to see if they behave properly.
If those tests go well, the team hopes to turn the elephant/mammoth skin cells into hybrid embryos that can be grown in artificial wombs, devices that allow for pregnancies outside of an animal’s uterus.