Mammoth RNA sequenced for the first time, marking a giant leap toward understanding prehistoric life
For the first time, scientists have successfully sequenced woolly mammoth RNA, shattering the hypothesis that this fragile genetic molecule could not have survived so long ago.
RNA, or ribonucleic acid, carries instructions between DNA and an organism’s protein-building machinery, acting as a messenger to transform genetic information into proteins. RNA can reveal which genes are active in a cell at any given time, as well as how patterns of gene activity within a cell change over time. Thus, ancient RNA can inform scientists about the cellular state of extinct species.
Although DNA provides a blueprint for an organism, there are limits to the information it reveals. RNA “opens a window into how” this plan is implemented in every cell of the body, study co-author said Zoe Pochondoctoral student at Stockholm University.
Messenger RNA (mRNA), aptly named, “is the messenger of DNA,” she told Live Science in an email. “In other words, it carries working copies of DNA instructions from the nucleus into the cell.” Other parts of the cell then follow these instructions, she added.
In the new study, published Friday November 14 in the log cellresearchers turned to 10 well-preserved woolly mammoths (Mammuthus primigenus) specimens from Siberia dating from 10,000 to 50,000 years ago. The team hoped that the freezing conditions would have preserved more specimens and thus produced better results.
One specimen in particular… Yukaa juvenile red-colored mammoth, gave spectacular results. Yuka is approximately 39,000 years old, making it the oldest RNA sequenced to date. Previously, this distinction was reserved for tissues taken from a canid dated to around 14,300 years ago.
Remarkably, scientists have discovered precise genetic signals indicating that Yuka, previously thought to be a female based on his physical attributes, is actually a man.
Additionally, RNA provided insight into Yuka’s muscle function, particularly RNA “creating the proteins that stretch and contract muscles,” said the study’s lead author. Emilio Marmol Sánchezwho worked at the Center for Evolutionary Hologenomics at the University of Copenhagen at the time of writing this article. The team also “discovered a whole set of regulatory genes,” he told Live Science.
When cells die, what is left is the last function of RNA. “What we are capturing here is, in a sense, a snapshot of the last moments of the lives of these mammoths” in their cells, said Mármol Sánchez.
What the team saw in Yuka’s muscle RNA reflects the potential horror of her final moments. Mármol Sánchez explained that he discovered “molecular evidence of metabolic cell stress in Yuka’s muscle”, which corresponds to the words of another scientific team. described in 2021. In this study, researchers noted numerous claw marks that may have been made by cave lions (Panthera spelaea), as well as bite marks from small predators on the mammoth’s body and tail. But it’s unclear whether Yuka was hunted and killed by large predators or simply scavenged after death. Researchers don’t know what caused the cellular stress seen in the RNA.
Federico Sanchez Quintopaleogenomicist at the International Human Genome Research Laboratory of the National Autonomous University of Mexico (UNAM), who was not involved in the research, considers it a “revolutionary publication in the field of paleogenomics.” He described the study as “fascinating because it achieves something that was previously unimaginable, because RNA is extremely unstable even under favorable conditions.” Additionally, “this study obtains RNA from an older sample [than other recent RNA work]in larger quantities and with more certainty,” he told Live Science in an email.
The results revealed that it is possible to extract RNA from extremely old specimens and present a potential new area of study for other researchers, the team said. Additionally, the team included a roadmap to help others successfully obtain ancient RNA.
“Being able to recover RNA from ancient samples, in addition to DNA, amounts to opening a new window on the biology of extinct animals,” co-author of the study I love Dalénprofessor of evolutionary genetics at the Center for Paleogenetics at Stockholm University, told Live Science. “This is yet another powerful tool that allows us to see which genes were active in different cell types, which can ultimately help us better understand which genes made a mammoth a mammoth!”
