Scientists genetically engineer mice with thick hair like the extinct woolly mammoth

On Tuesday, Colossal announced that its scientists have simultaneously edited seven genes in mice embryos to create mice with long, thick, woolly hair. They nicknamed the extra-furry rodents as the “Colossal woolly mouse.”

Results were posted online, but they have not yet been published in a journal or vetted by independent scientists.

The feat “is technologically pretty cool,” said Vincent Lynch, a biologist at the University of Buffalo, who was not involved in the research.

Scientists have been genetically engineering mice since the 1970s, but new technologies like CRISPR “make it a lot more efficient and easier,” said Lynch.

The Colossal scientists reviewed DNA databases of mouse genes to identify genes related to hair texture and fat metabolism. Each of these genetic variations are “present already in some living mice,” said Colossal’s chief scientist Beth Shapiro, but “we put them all together in a single mouse.”

They picked the two traits because these mutations are likely related to cold tolerance — a quality that woolly mammoths must have had to survive on the prehistoric Arctic steppe.

Colossal said it focused on mice first to confirm if the process works before potentially moving on to edit the embryos of Asian elephants, the closest living relatives to woolly mammoths.

However, because Asian elephants are an endangered species, there will be “a lot of processes and red tape” before any plan can move forward, said Colossal’s Lamm, whose company has raised over $400 million in funding.