Scientists have obtained RNA from an extinct species for the first time | Albiseyler

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For the first time, geneticists have isolated and decoded RNA molecules from a creature that died out long ago.

Genetic material from a 130-year-old specimen of the Tasmanian tiger, or thylacine, in the collection of the Swedish Museum of Natural History in Stockholm has given scientists a better understanding of how the animal’s genes worked. The researchers shared their findings in a study published Tuesday in the journal Science Genome research.

“RNA gives you a chance to go through the cell, the tissues, and find the actual biology that was preserved in this animal, the thylacine species, right before death,” said the study’s lead author Emilio Mármol Sánchez, a computational biologist. at the Center for Paleogenetics and SciLifeLab in Sweden.

The thylacine was about the size of a coyote and was a marsupial predator. It disappeared about 2000 years ago practically everywhere except the Australian island state of Tasmania, where the population was hunted to extinction by European settlers. The last captive thylacine, named Benjamin, died of exposure in 1936 at Beaumaris Zoo in Hobart, Tasmania.

Mármol Sánchez said that while the goal of his team’s research was not extinction, a better understanding of the genetic make-up of the Tasmanian tiger could help recently launch efforts to bring the animal back in some form.

Andrew Pask, who leads a project to resurrect the thylacin, he said the paper was “groundbreaking”.

“We used to think that only DNA remained in old museums and ancient specimens, but this paper shows that you can also get RNA from tissues,” said Pask, a professor at the University of Melbourne in Australia and head of the Thylacine Integrated Genetic Restoration Research Laboratory. Lab. .

“This will greatly advance our understanding of the biology of extinct animals and help us build much better extinct genomes,” he added.

Ancient DNA can last over a million years under the right conditions and has revolutionized scientists’ understanding of the past.

RNA, a temporary copy of a stretch of DNA, is more fragile and breaks down faster than DNA and, until recently, was not thought to last for any length of time.

In 2019, the team sequenced RNA from the skin of a 14,300-year-old wolf which was preserved in permafrost, but the latest research is the first time that RNA has been obtained from an animal that is now extinct.

Mármol Sánchez said the study is a proof of concept, and his colleagues now hope to obtain RNA from animals that died out much earlier, such as the woolly mammoth.

The research team was able to RNA sequence skin and skeletal muscle tissue from the sample and identify genes specific to the thylacine. This information forms part of what is known as the animal’s transcriptome, just as the information stored in DNA is known as the genome.

DNA is often described as the instructions for life contained in every cell of the body. Among other cellular functions, RNA produces proteins by making a copy of a particular section of DNA in a process known as transcription.

Understanding RNA allows scientists to piece together a more complete picture of the animal’s biology, Mármol Sánchez he said. He uses the analogy of a city where every restaurant is given one giant recipe book — the DNA. However, it is RNA that allows each restaurant to produce different dishes from this reference book.

“If you only focus on DNA, you won’t be able to capture the differences between all these restaurants,” said Mármol Sánchez. “With RNA… now you can go to a restaurant and taste food, taste paella, sushi or sandwiches.”

“You can learn a lot … by reading those recipes,” he added, “but you’re going to miss the actual bits of metabolism, biology, that all those restaurants or cells have between them.”