Woolly mammoth RNA extracted and sequenced

Researchers at Stockholm University have extracted and sequenced the oldest known RNA molecules in the world (Cell 2025, DOI: 10.1016/j.cell.2025.10.025). The ancient RNA (aRNA) comes from skin and muscle tissue of 10 woolly mammoths that had been frozen for around 40,000 years. One of the samples provides a biological time capsule of gene expression just before death. Ancient DNA (aDNA) studies have transformed our understanding of extinct and extant organisms that lived up to 2 million years ago. By comparing genetic data from these organisms with those from modern relatives, aDNA studies can provide a broader picture of evolutionary changes over time. “But while aDNA can tell us where we come from and how we came to be what we are,” says Emilio Mármol Sánchez, one of the lead authors of this study, “with aRNA, we can directly assess which genes were being actively expressed and explore the vast universe of noncoding RNA molecules.”But as any scientist who has worked with RNA will tell you, RNA is a more fragile molecule than DNA, and ribonucleases act quickly to destroy it. This has meant aRNA studies have remained scarce and are still in their early stages. To expand the limited aRNA record, Mármol Sánchez and his team turned to great woolly mammoths that had been preserved in the Siberian permafrost.After collecting permafrost-preserved skin and muscle tissues from 10 woolly mammoths, the team screened all of the genetic material in each sample, including possible contaminants. They found a lot of mammoth-like aDNA