Scientists have extracted the world's oldest RNA from a 40,000-year-old woolly mammoth preserved in Siberian permafrost. The specimen, known as Yuka, provides insights into gene activity at the time of its death. This discovery nearly triples the previous record for ancient RNA recovery.
In 2010, researchers discovered Yuka, regarded as the best-preserved woolly mammoth (Mammuthus primigenius) ever found, frozen in the Siberian permafrost for nearly 40,000 years. Initially believed to be a juvenile female who died between 6 and 8 years old, possibly after an attack by cave lions, Yuka's remains yielded the oldest RNA sample to date.
Love Dalén at Stockholm University in Sweden and his colleagues extracted RNA from one of Yuka’s legs, surpassing the previous record from a wolf preserved over 14,000 years ago. The team adapted techniques used for fresh specimens to handle the degraded, fragmented molecules. “Yuka is exceptionally well preserved,” says Dalén. “The specimen likely underwent rapid freezing and long-term burial in permafrost, as evidenced by the preservation of both the muscle tissue and the woolly fur. This greatly increases the chances of RNA to have been preserved.”
Challenges included a brief thaw during transport from north-east Siberia to Yakutsk, prompting careful measures like using liquid nitrogen for grinding samples, sterile materials, filtered air, protective suits, and a controlled lab to prevent contamination. The RNA revealed gene activity linked to muscle metabolism and cell stress, aligning with a violent death such as a cave lion attack.
Analysis confirmed Yuka was male, contrary to initial assumptions. “I have been around long enough to know that these things happen,” says Dalén. “Yuka is well preserved for being 40,000 years old, but not completely intact, so it is not always easy to morphologically sex an individual.” No RNA viruses like influenza or coronaviruses were found, though Dalén anticipates future studies on ice age pathogens.
While not directly aiding de-extinction efforts—Dalén advises Colossal Biosciences—the RNA offers insights into genetic traits like mammoth hair. Merlin Crossley at the University of New South Wales calls it a remarkable feat but questions its biological insights: “It’s a little bit like flying a light plane under the Sydney Harbour Bridge. It’s an impressive technical feat, but I’m not sure what we learned from it.” He notes such preservation is rare, nearing RNA's survival limit.
The findings appear in Cell (DOI: 10.1016/j.cell.2025.10.025).