3D reconstruction of woolly mammoth genome could help revive extinct species

Scientists have recreated the three-dimensional structure of the woolly mammoth’s genetic heritage.

The achievement, described Thursday in the journal Cell, marks what appears to be the first time scientists have been able to produce a multidimensional version of the genome of a complex extinct species.

The advance is expected to provide important new insights into the biology of a creature that has long fascinated people. In addition, the work could aid efforts to create a living version of the animal, the researchers and others said.

“It’s exciting,” says Aiden Erez Lieberman, professor of molecular and human genetics and director of the Center for Genome Architecture at Baylor College of Medicine in Houston. “We think it’s going to be very useful.”

For years, scientists have been able to go back in time by analyzing fragments of ancient DNA recovered from bones, fossilized teeth, mummies and even strands of hair.

“In biology, one of the most powerful tools for understanding the history of life on this planet is ancient DNA,” Aiden says. “It’s an incredibly powerful tool for understanding the history of life.”

But scientists can’t learn everything from fragments of DNA, so Aiden and his colleagues have launched an international initiative to try to recreate the three-dimensional structure of DNA, including chromosomes, from an extinct creature.

“By doing this, you would be able to see exactly how that chromosome was formed in a living cell, and you would be able to gain a deeper understanding of the genomes of ancient and extinct species and how those genomes function – which genes are turned on and off in particular tissues,” Aiden says.

Looking for Mammoth Samples on eBay

Scientists focused on the woolly mammoth, a large, shaggy elephant species that roamed the tundra thousands of years ago.

“At first, we had some really bad ideas. I’m a little ashamed to admit it,” Aiden told NPR. “We were like, ‘Oh, you know, this looks like a nice piece of mammoth on eBay. Let’s try it.’ It’s a little embarrassing, isn’t it, to tell you. eBay is not a good place to buy mammoth samples.”

After five years of searching, the team finally found a well-preserved mammoth sample: the skin from behind the ear of a 52,000-year-old female, discovered freeze-dried in Siberia in 2018.

“This was a piece of mammoth hide that was wooly. As the name suggests, it was indeed a wooly mammoth hide,” says Olga Dudchenko, an assistant professor at the Baylor Center for Genome Architecture who was involved in the study. “And it’s not as insignificant as it sounds, because very often the hairs were missing. So this one was hairy. And that in itself is an interesting indicator of the quality of this sample. And that immediately caught our attention.”

Scientists can examine individual genes of mammoths

In fact, the quality of the sample allowed the team to extract the DNA and use a technique known as Hi-C to reconstruct the three-dimensional structure of the mammoth’s 28 chromosomes, the extinct creature’s entire genome, the researchers reported.

“We were able to assemble the genome of a woolly mammoth, just like 25 years ago humans were eager to be able to assemble their own genome,” Aiden says. “Now we can do it for animals that have been extinct for a long time. That’s obviously a big step.”

Additionally, the team was able to examine the genome to begin to understand the role of individual genes.

“It’s really exciting to be able to look at an extinct creature and be able to say, ‘Oh, yeah. I can see this gene was on. This gene was on. This gene was off. Oh, isn’t that surprising?’” Aiden says. “To be able to do all these specific things in a woolly mammoth is exciting.”

In fact, by comparing the mammoth genome to the DNA of modern elephants, scientists have already discovered clues about what made the woolly mammoth woolly.

“We have discussed internally the possibility of creating a Hair Club for mammoths?” jokes Dudchekno.

Genetic discoveries could help bring back mammoths

But seriously, this discovery could help efforts already underway to try to bring a version of the mammoth back from extinction — by giving modern Asian elephants mammoth features, like hair, and perhaps even releasing them to graze on the tundra again.

“I think it can be useful in combating extinction,” Aiden says.

Other scientists have praised the work.

“I think it’s pretty cool,” says Vincent Lynch, an associate professor of biological sciences at the University at Buffalo, who was not involved in the research.

But Lynch is not a big fan of the idea of ​​bringing mammoths back to life. The unintended consequences of such a move could be disastrous, he says. And the money earmarked for such a project would be better spent trying to save the elephants that still roam the planet today.

“The potential for unintended consequences is enormous,” Lynch says. “Think about all the other invasive species out there. You don’t really know what effect a species will have on the environment until it’s there.”

And Karl Flessa, a professor of geosciences at the University of Arizona, acknowledges the scientific feat and the folly of trying to bring back the extinct pachyderm.

“The preservation of the genetic architectures of the woolly mammoth is truly remarkable,” Flessa says. “But just because it can be done doesn’t mean it should be done. A genetically modified Asian elephant is not a woolly mammoth. And releasing such an animal into the wild would be arrogant and irresponsible.”

Others disagree.

“It is exciting to see that 3D architecture can be preserved in ancient samples. This will help move toward a complete de novo assembled mammoth genome, which could reveal features of the genome that could be relevant to mammoth de-extinction,” Eriona Hysolli, who leads a project to create an Asian elephant with mammoth features at Colossal Laboratories & Biosciences in Dallas, wrote in an email to NPR.

Still, Robert Fleischer, a senior scientist at the Center for Conservation Genomics at the Smithsonian’s National Zoo & Conservation Institute in Washington, says the prospect is exciting.

“If I was 12 years old and in my middle school science class, I would probably think this was pretty cool,” Fleischer says. “And I still think it’s pretty cool.”