A company called Colossal Biosciences has created thick-haired mice that they are calling “Colossal Woolly Mice”. The mice, created by editing DNA, are meant to be a step toward the company’s larger goal of recreating the extinct woolly mammoth. Not everyone thinks it’s a great idea.
Colossal is a company that is focused on replacing some animals that went extinct long ago. Its main project is to recreate woolly mammoths. Woolly mammoths, which look like a hairy version of modern elephants, died out about 4,000 years ago, after the end of the last ice age.
Two woolly mice created by Colossal are seen over the company's logo.
A company called Colossal Biosciences has created thick-haired mice that they are calling “Colossal Woolly Mice” (above). The mice, created by editing DNA, are meant to be a step toward the company’s larger goal of recreating the extinct woolly mammoth.
(Source: Colossal Biosciences.)
Colossal isn’t trying to bring woolly mammoths back to life. Instead, it wants to change DNA from Asian elephants to create an animal similar to a woolly mammoth. The company believes bringing this kind of animal back to the Arctic could help restore balance to the environment there. Some scientists question this.
Actually working with Asian elephants would be very difficult. For one thing, they’re endangered. For another, it takes them 22 months to produce a baby.
Mammoth, Royal BC Museum, Victoria, Canada
Woolly mammoths died out about 4,000 years ago, after the end of the last ice age. Colossal wants to change DNA from Asian elephants to create an animal similar to a woolly mammoth. Above, a mammoth exhibit at the Royal BC Museum in Victoria, Canada.
(Source: jan zeschky, via Flickr.com.)
So the scientists at Colossal decided to focus on mice instead. Mice have many advantages for experimenting. Scientists are already used to working with mice. They are small, cheap, and easy to work with. And it only takes 20 days for mice to have babies.
Editing DNA
DNA is a collection of information and instructions stored in a tiny chemical form. DNA tells cells, the building blocks of a body, what to do. Every living thing has DNA that causes it to grow in a certain way.
Small bits of DNA, called “genes”, help control different parts of how a living thing grows. For example, some genes might control eye color. Some genes work by themselves, others work together. Some may help control more than one thing. There’s still a lot that scientists don’t understand about DNA.
In recent years, scientists have made great progress in their ability to “edit” DNA. CRISPR is a tool that allows scientists to cut out or change a piece of DNA. They can even replace a gene with something new. But editing DNA is tricky. Since genes are complicated, changing them can have unexpected effects.
This image shows the coding region in a segment of eukaryotic DNA.
DNA is a collection of information and instructions stored in a tiny chemical form. Small bits of DNA, called “genes”, work to control different parts of how a living thing grows. In recent years, scientists have made great progress in their ability to “edit” DNA with a tool called CRISPR.
(Source: Smedlib, from Wikimedia Commons.)
For the experiment, the researchers focused on things that helped protect mammoths from the cold. One of these things was their long, thick hair.* Colossal scientists looked at the differences between the DNA of woolly mammoths and the DNA of elephants.
Then, they tried to make some of those same changes in the DNA of mice. Scientists already know a lot about the DNA of mice. That made it easier for the researchers to choose genes that are known to affect things like how long or thick the hair grows, or what color it is.
A woolly mouse created by Colossal is seen next to a normal lab mouse, both in the gloved hands of a handler.
Colossal scientists looked at the differences between the DNA of woolly mammoths and the DNA of elephants. Then, they tried to make some of those same changes in the DNA of mice. Above, a woolly mouse next to a normal lab mouse.
(Source: Colossal Biosciences.)
Using CRISPR, the researchers edited mouse DNA to change not just one gene, but as many as seven genes at one time. That’s a big part of what makes this experiment special.
The results were striking. As lead scientist Beth Shapiro described it, “We ended up with some absolutely adorable mice that have longer, woolly, golden-colored coats.”
The results are very good news for Colossal. Since the company plans to use elephant DNA to create something like a mammoth, they will need to edit many, many genes – perhaps as many as 85. The company is pleased that it has been able to target these genes for hair so quickly and accurately.
Three woolly mice created by Colossal are seen on the gloved hand of a handler.
Colossal’s researchers edited as many as seven genes at one time. The results (above) were striking. As lead scientist Beth Shapiro described it, “We ended up with some absolutely adorable mice that have longer, woolly, golden-colored coats.”
(Source: Colossal Biosciences.)
Many outside experts were impressed with Colossal’s ability to edit many genes at once. But not everyone thinks the woolly mice are such a big deal.
Some people even question Colossal’s plans to bring back extinct animals. They say it might be better to put the money and effort toward trying to help animals that are in danger of going extinct right now.
Colossal believes that its work could wind up being helpful in many situations – including protecting endangered animals.
Did You Know…?
In addition to recreating woolly mammoths, Colossal also hopes to bring back two other extinct species: the Tasmanian tiger and a large flightless bird called the dodo.
* Colossal’s researchers also changed the mice genes to make the mice use their body fat more like mammoths did.