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

Colossal announced that its scientists have simultaneously edited seven genes in mice embryos to create mice with long, thick, woolly hair

Extinction is still forever, but scientists at the biotech company Colossal Biosciences are trying what they say is the next best thing to restoring ancient beasts — genetically engineering living animals with qualities to resemble extinct species like the woolly mammoth.

Woolly mammoths roamed the frozen tundras of Europe, Asia and North America until they went extinct around 4,000 years ago.

Colossal made a splash in 2021 when it unveiled an ambitious plan to revive the woolly mammoth and later the dodo bird. Since then, the company has focused on identifying key traits of extinct animals by studying ancient DNA, with a goal to genetically “engineer them into living animals,” said CEO Ben Lamm.

Outside scientists have mixed views about whether this strategy will be helpful for conservation.

“You’re not actually resurrecting anything — you’re not bringing back the ancient past,” said Christopher Preston, a wildlife and environment expert at the University of Montana, who was not involved in the research.

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.