Scientists create ‘woolly mice,’ a step toward reviving woolly mammoth

ISTANBUL (AA) - Scientists have successfully engineered mice to grow woolly hair, which they say is a major step toward bringing back the woolly mammoth.

Scientists at the American biotech company Colossal Biosciences aim to have the first woolly mammoth calf by 2028. By comparing ancient mammoth DNA with that of Asian elephants, they have begun gene editing to recreate mammoth traits.

CEO Ben Lamm described the so-called woolly mice as “a massive validating point” for their approach, according to the Guardian.

"These mice are massively adorable. They are significantly cuter than we anticipated, which probably means that our first-generation mammoths will also be equally as cute,” Lamm said on X.

In their yet-to-be peer-reviewed study, researchers say they used genome editing to modify fertilized mouse eggs or embryonic stem cells before implanting them into surrogates.

They targeted nine genes linked to hair traits, aiming to mimic mammoth-like golden hair. Two of these genes, also found in mammoths, were altered to resemble their woolly coat, while another gene tied to fat metabolism was modified to potentially aid cold adaptation.

Using advanced techniques, the team made up to eight edits across seven genes simultaneously.Many experiments failed to produce live mouse pups, but those that did resulted in mice with woolly, long or golden-brown coats. Scientists also say the mice have fat similar to that of the mammoth. Lamm said that the team plans to test cold tolerance soon.

Colossal aims to start by “de-extincting” the woolly mammoth but eventually move on to other extinct animals to “preserve and restore Earth’s diminishing biodiversity.”

The woolly mammoth went extinct around 4,000 years ago.

- A mouse is not a mammoth, scientists say

Despite technical praise, some scientists remain skeptical about the project’s feasibility.

Robin Lovell-Badge, head of stem cell biology at the Francis Crick Institute in London acknowledged the technical skill involved but emphasized that reviving mammoths is far more complex than modifying a few genes.

“As it is, we have some cute-looking hairy mice, with no understanding of their physiology, behavior,” he told The Guardian.

He also questioned whether this was a better use of resources than preventing species extinction.

Other experts clarified that no mammoth genes were used, only modifications to mouse genes.

Tori Herridge, an evolutionary biologist at the University of Sheffield told The Guardian that engineering a mammoth-like elephant is a much greater challenge, as more genes are involved and many remain unidentified.

“Mammoth de-extinction doesn’t seem to be on the horizon anytime soon,” he said.