52,000-year-old scrap of woolly mammoth skin reveals 3D shape of its DNA for 1st time ever

A 52,000-year-old woolly mammoth carcass was so well preserved, scientists were able to determine the 3D structure of the prehistoric creature's genetic code, a first-of-its-kind study shows.

The new breakthrough is a significant step on the path to sequencing a complete woolly mammoth (Mammuthus primigenius) genome, which has been challenging due to the degraded nature of ancient DNA. With a completely sequenced genome, scientists may finally be able to identify every single DNA mutation that differentiates modern elephants from their woolly mammoth relatives. A full overview of these genetic differences could in turn boost ongoing efforts to "de-extinct" the woolly mammoth.

"Until now, we could only read small fragments of ancient DNA," co-author Juan Antonio Rodríguez, an assistant professor of hologenomics at the University of Copenhagen in Denmark, told Live Science in an email. "These fragments were about 100 letters of DNA, but we did not know what order they had in the mammoth genome. It is like separated pages of a book, but without the page number." 

The results of the new study, published Thursday (June 11) in the journal Cell, will enable researchers to "put an order to those pages," Rodríguez said. This is the oldest 3D genome analysis ever completed and the first done in a woolly mammoth, he said.

The woolly mammoth in question is a late Pleistocene specimen discovered in 2018 near Belaya Gora, in the Sakha Republic of Siberia. The animal, nicknamed "YakInf," was still covered in hair, indicating it was "exceptionally well preserved," Rodríguez said.

Related: Mystery 'random event' killed off Earth's last woolly mammoths in Siberia, study claims

The mammoth died and froze in a way that crystalized not only its carcass, but also its cells and chromosomes, which stayed intact for 52,000 years. According to the study, this suggests the mammoth underwent both freeze-drying — dehydration at cold temperatures — and a process called glass transition, where under cold conditions, certain dry materials — including glass and, seemingly, woolly mammoth tissues — can become extremely viscous. This process slows down degradation and preserves their structure in a "glassy" state.