meanwhile, last ice ageOccurred between 115,000 and 11,500 years ago, woolly mammoth They lived on the frozen plains of Eurasia and North America. As the Earth warmed, this species with thick fur and ivory tusks gradually disappeared. And just 4,000 years ago, only a few groups were able to survive on remote islands in the Arctic Circle. Now, thousands of years later, a group of researchers has achieved: RNA molecules were successfully isolated and sequenced from these mammoths.represents the oldest array ever recovered.
Researchers at Stockholm University were able to extract this sequence from the tissues of several specimens that had been preserved in Siberian permafrost for 40,000 years. Ribonucleic acid (RNA), demonstrating that not only DNA and proteins can be stored For such a long time. The discovery provides a new perspective on the biology of a species that has been extinct for thousands of years and opens up new horizons for the analysis of Earth’s ancient inhabitants.
Until now, advances in the study of extinct species have relied almost exclusively on DNA to help reconstruct genomes and trace evolutionary lineages. However, RNA (a molecule that reveals which genes are expressed within an organism) was thought to be too fragile to survive after death. “Using RNA You can get direct evidence of which genes were activesomething that would be impossible to discover using DNA alone,” explains Emilio Marmol, a researcher at the Globe Institute and lead author of the study.
The team analyzed Muscular remains of baby mammoth Yuka found in Siberia It is in an exceptional state of preservation. Of the mammoth’s more than 20,000 coding genes, scientists detected only those that were actually active during the time the animal was alive. Among them are genes associated with muscle contraction and metabolic responses to stress situations. “We found Signs of cellular stress“This is not surprising, as previous research suggested that Yuka was attacked by a cave lion shortly before her death,” the researchers explain.
Oldest RNA ever sequenced
In addition to messenger RNA, researchers have discovered a variety of other RNAs. microRNA, Regulatory molecules that control gene activity. According to Professor Mark Friedlander of the Wenner-Gren Institute and Cylife Lab, this finding is particularly revealing: “The muscle-specific microRNAs we discovered are direct evidence of gene regulation occurring in real time in ancient times.” This is the first time that something like this has been achieved”.
The microRNAs also contained unique mutations found only in mammoths, making it possible to verify the origin of the samples. They were also detected previously unknown genes This study, based solely on molecular evidence, is unprecedented in the study of extinct species. To Mr. Bastian Fromm of the Norwegian Arctic University Museum
This discovery has far-reaching implications. According to Rab Dalen, professor of evolutionary genomics at the Center for Paleogenetics, these RNA molecules “sequence virus Darren points out that this is an area of research for RNA, such as influenza and coronaviruses, preserved in Ice Age ruins. Until now it was thought to be virtually impossible This is because these molecules are fragile.
In future studies, the researchers will combine information from RNA, DNA, proteins, and other biomolecules to more accurately reconstruct the ecology and evolution of extinct megafauna. Progress is “possible” Fundamentally changing our understanding of extinct megafauna “We are uncovering multiple hidden layers of biology that until now remained frozen in time,” concludes lead author Emilio Marmol.
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