Scientists reconstruct DNA from 52,000-year-old woolly mammoth

• As biotech start-ups work on ways to bring back the woolly mammoth, an international team of scientists has reconstructed 28 pairs of chromosomes from the iconic Ice Age animal.
• This genetic breakthrough was facilitated by a chromosome taken from a 52,000-year-old mammoth that was fortunately frozen and dried out shortly after its death in northeastern Siberia.
• This fossilised chromosome is the first of its kind to be discovered and provides unprecedented detail about the woolly mammoth genome, as well as its genetic relationship to its closest living cousin, the Asian elephant.

Although the idea of ​​resurrecting long-dead animals didn’t really become popular until 1993, Jurassic Parkmuch of the talk about de-extinction revolves around another icon of the not-so-distant past: the woolly mammoth. And while John Hammond was wrong about many things—for example, don’t put man-eating animals in your theme park—he was right about one thing: to bring an animal back from oblivion, you need genetic information. And lots of it.

In the case of the woolly mammoth, ancient DNA remnants have been found buried in fossils recovered from Earth’s frozen tundra, but this information contains only about 100 base pairs, far too little to provide a complete genetic picture of this majestic, thick-skinned animal. However, a new international study led by Rice University scientists has successfully uncovered the fossilized chromosome of a 52,000-year-old mammoth that was essentially frozen after death in what is now Siberia. Instead of containing the usual 100 base pairs, this chromosomal finding is more than a million times longer and shows both how the genome was organized in living cells and what genes were active in its skin tissue. The results of the study were published in the diary Cell.

“Copanetic chromosomes are a game-changer,” said Olga Dudchenko of Baylor University, a co-author of the study. he said in a press statement“Knowing the shape of an organism’s chromosomes allows us to piece together the entire DNA sequence of extinct creatures, providing insights that were previously impossible.”

Not surprisingly, the team found that the woolly mammoth had 28 pairs of chromosomes, the same number as modern Asian elephants, and that active genes in its skin stimulated the growth of hair follicles, giving woolly mammoths their fur.

“For the first time,” said Marc Marti-Renom, a researcher at the Centre Nacional d’Anàlisi Genòmica in Barcelona and co-author of the study: he said in another press statement“We have tissue from a woolly mammoth where we know roughly which genes were turned on and which were turned off. This is an extraordinary new type of data and the first measurement of cell-specific gene activity in any ancient DNA sample.”

The researchers were able to create a 3D model of the chromosomes without relying on existing elephant data. This is largely because the beneficial freeze-drying process preserved the chromosomes in a glass-like state, meaning that individual pieces of DNA could not move far and their structures were preserved through biological ages.

The team then used a technique known as “Hi-C,” which allows researchers to detect which parts of DNA interact with each other in the nucleus, a process Marti-Renom describes as trying to solve a three-billion-piece jigsaw puzzle without even having a picture of the final image to look at. Finally, the researchers combined that data with DNA sequencing to create a map of the woolly mammoth genome.

Although biotech startups are eager to revive the woolly mammoth, many experts have warned against trying to bring back the species, arguing that at best, humans would create a hybrid elephant that doesn’t really fit in with the natural world, and at worst, we’d introduce an invasive species to the Arctic tundra. For now, this data will help scientists better understand how genomes drive changing traits in different environments, but one day this chromosomal model could help resurrect an Ice Age icon.

Another positive? At least woolly mammoths don’t eat humans.

Darren lives in Portland, has a cat, and writes/edits about science fiction and how our world works. You can find his previous work on Gizmodo and Paste if you search hard enough.