Siberia – In a breakthrough that challenges long-held assumptions about the durability of biomolecules, scientists have successfully recovered and sequenced ancient Ribonucleic Acid (RNA) from the frozen remains of a woolly mammoth. The discovery, detailed in the journal Cell, provides an unprecedented molecular snapshot of an animal that lived nearly 40,000 years ago, offering a rare look into its cellular activity and final moments.
The RNA was extracted from muscle tissue belonging to a juvenile male mammoth named Yuka, whose remarkably preserved carcass was found near the Laptev Sea coast in Siberian permafrost. RNA, which acts as a crucial messenger carrying instructions from DNA to create proteins, was previously thought to decay within minutes or hours of death, making its survival over forty millennia truly exceptional.
Permafrost: A 40,000 Year-Old Time Capsule
The extraordinary preservation of the RNA is attributed to the stable, deep-frozen conditions of the Siberian permafrost. The rapid burial of the mammoth in dense frozen soil, combined with long-term cold temperatures, created a natural vault that shielded the remains from moisture, bacteria, and fluctuating temperatures conditions essential for slowing the rapid molecular decay typically seen after death. This exceptional environment has preserved much of Yuka’s soft tissue, including skin and muscle, with remarkable clarity.
The fact that such fragile material endured for almost forty millennia illustrates how powerful the preserving effect of permanently frozen landscapes can be. This find pushes the known endurance threshold of ancient RNA significantly and highlights the scientific value of these frozen archives, especially as climate change threatens to thaw permafrost regions and destroy their contents.
A Glimpse into the Mammoth’s Last Moments
Once extracted using specialized, contamination-controlled laboratory methods, the fragmented RNA sequences provided scientists with a set of clues about Yuka’s biology at the time of its death.
The key significance of RNA lies in its ability to show gene expression that is, which genes were “turned on” in the living tissue. Analysis of the transcripts revealed:
• Cellular Activity: The recovered RNA contained enough information to identify genes involved in muscle structure, cellular maintenance, and energy use, suggesting the mammoth’s cells were performing normal functions shortly before death.
• Signs of Stress: Researchers detected transcripts linked to stress responses and metabolic regulation, suggesting the animal may have experienced significant physical strain or environmental pressure near the end of its life. This aligns with previous findings indicating Yuka may have been attacked by predators, such as a cave lion, shortly before it died.
• Genetic Confirmation: By comparing the sequences with the genomes of modern elephants, the mammoth’s closest living relatives, researchers confirmed the authenticity of the ancient RNA. They also successfully identified unique microRNAs molecules that regulate gene activity providing direct evidence of gene regulation in ancient times.
This research marks a major advancement in palaeogenomics, offering a level of biological detail that traditional fossil evidence cannot. Scientists now believe that under ideal conditions, it may be possible to recover RNA from even older remains, opening a new door to studying the functioning of other extinct megafauna and even sequencing ancient RNA viruses trapped in Ice Age remains.