Scientists have done something revolutionary. They’ve created a ‘woolly mouse’: a small rodent with thick, golden brown fur based on the woolly mammoth. Its company, Colossal Biosciences, believes that this small, fluffy creature will help bring back mammoths in 2028.
Cute But Important
“The mice weren’t supposed to be this cute,” said Ben Lamm, CEO of Colossal. The mice are not just for show. They are part of a larger experiment testing gene edits that could one day make elephants look like their extinct cousins, mammoths.
From Mice to Mammoths
Woolly mammoths were active during the ice age. They had thick fur and fat deposits, protecting them from the extreme weather. Trying to give these same characteristics to elephants is not straighforward. Experimenting with mice is much easier. They are small, breed quickly and allow researchers to hone in on genetic alterations before attempting to move up the animal chain.
The Science Behind the Fluff
Seven genes were edited to create woolly mice. Six of them regulate the fur density, length and colour. Rather than using actual mammoth genes they identified similar ones in the mouse and flipped the switch that made their coat resemble mammoths’ coat texture.
Turning Off the Right Genes
One key gene, FGF-5, is responsible for controlling hair length. The mice developed fur three times longer than normal mice when scientists shut off this key gene. Each genetic edit brought the mice a little closer to resembling prehistoric elephants.
Fat and Cold Tolerance
Mammoths also had a layer of fat to keep them warm in cold climates. The team of scientists also tried to give the mice the same advantage through modifying a gene that regulates fat production. However, the effects were not very well defined: more studies are needed to assess whether the mice are more tolerant to cold conditions.
Speedy Science
Mice are best suited for this kind of research. As opposed to elephants, which have a 22 month pregnancy, mice can give birth in as little as 20 days. This means that the researchers can develop, experiment on, and improve their woolly mice in just six months: something that cannot be accomplished when working with a larger animal.
High-Tech Gene Editing
Scientists employed three different gene-editing techniques, including a method called multiplex precision genome editing. It enabled them to alter several genes at a time with a high degree of precision. This would be an essential process to master before applying the same technology to elephants.
What Experts Think
“Definitely a proof of concept,” said Vincent Lynch, an evolutionary biologist, who was not involved in the study. In other words, if they can stack up several gene edits in mice and get mammoth-like fur, then they can do the same in elephants. But there’s a catch.
The Elephant Problem
Elephants are practically hairless by nature. Even if scientists introduce these mutations to Asian elephants (the closest living relatives of mammoths), they will not grow a dense woolly coat like mammoths. More gene edits will be needed to increase hair density.
Real-World Tests Are Next
Up until now, woolly mice have only been bred and experimented on in a laboratory. But soon, Colossal will be testing their cold tolerance. If they are better than regular mice in cold conditions, it will represent a victory for the mammoth project. If not, scientists will have to get back to work.
The Long Road Ahead
Whilst wooally mice are a fun milestone, bringing back mammoths is still a long way away. Genetic engineering on elephants is much more complicated, and ethical issues are still outstanding. But one thing is sure: Science is closing in on making de-extinction a reality.
The Future of De-Extinction
If Colossal succeeds, it won’t just be mammoths. The company also believes in restoring other extinct species like the thylacine (Tasmanian tiger). For now, their woolly mice are evidence that small steps can result in big strides.
