For the first time scientists have isolated and sequenced RNA molecules from woolly mammoth remains preserved in Siberian permafrost. The material, taken from frozen muscle, is nearly 40,000 years old and represents the oldest RNA ever recovered. The finding shows that RNA, like DNA and proteins, can survive for very long periods and may provide new information about extinct animals.
The research team analysed tissue from Yuka, a juvenile mammoth that died almost 40,000 years ago. The lead author, Emilio Mármol of the Globe Institute, University of Copenhagen, said RNA gives direct evidence of which genes were "turned on" in cells. The work involved collaborators at SciLifeLab and the Centre for Palaeogenetics, a joint initiative of Stockholm University and the Swedish Museum of Natural History. Love Dalén noted that the group had already pushed DNA recovery "past a million years" and wanted to test whether RNA sequencing could go further back in time.
The recovered RNA can reveal gene activity at or near the time of death, which is different from the information that DNA alone provides. The authors argue that combining RNA data with DNA, proteins and other preserved biomolecules could reveal new layers of biology in extinct species. The researchers hope future studies will use multiple types of ancient molecules to improve knowledge of extinct megafauna and other species. The study appears in the journal Cell and was reported by the University of Copenhagen.
Difficult words
- isolated — to separate something from other material
- sequenced — to determine the exact order of genetic units
- permafrost — ground that stays permanently frozen
- preserved — to keep something safe and unchanged
- recovered — to find or get back something lost
- gene — a DNA segment that controls traitsgenes
- megafauna — very large animals, often from the past
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- The article says recovered RNA can show which genes were "turned on". How might this information change our understanding of extinct animals? Give one or two examples.
- Why was permafrost important for this discovery? Explain how permafrost helps preserve biological material.
- The authors suggest combining RNA with DNA, proteins and other biomolecules. What benefits could this combined approach bring to the study of extinct megafauna?
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