Scientists have successfully reconstructed the three-dimensional structure of the woolly mammoth chromosomes, thanks to a perfectly preserved piece of dry skin found in permafrost in Siberia for 52,000 years.
The research team extracted DNA from a piece of skin taken from behind the ear of the woolly mammoth (Mammuthus primigenius). They utilized a method known as High-Capacity Chromosome Conformation Capture (Hi-C), which allows for the detection of DNA segments that are located close to each other in modern samples and adjusted it for use on ancient samples.
Scientists examining a 52,000-year-old woolly mammoth skin sample – (Photo: Stockholm University).
According to ScienceAlert on July 12, this unique technique allowed scientists to determine for the first time that woolly mammoths had 28 pairs of chromosomes, similar to modern elephants. This also marks the first time that scientists have been able to count the chromosomes of an extinct animal.
The study also revealed “the precise way these chromosomes folded into three-dimensional structures within the cell nucleus of the woolly mammoth’s skin.”
“This is fascinating because we know that how chromosomes fold is closely related to cellular function,” said co-author Olga Dudchenko, who works in the Department of Genetics at Baylor College of Medicine (USA).
Dry skin sample of the woolly mammoth – (Photo: Stockholm University).
The last woolly mammoths on Earth died about 4,000 years ago. Scientists have to trace the remnants they left behind to understand the life and history of this species.
Luckily, they lived in a frigid environment, which allowed many things to be well-preserved. The aforementioned piece of woolly mammoth skin was discovered in the Siberian tundra in 2018.
Chromosomes from the woolly mammoth fossil represent a significant breakthrough, as knowing the shape of a creature’s chromosomes can help piece together the entire DNA sequence of extinct organisms. “This allows us to gain insights into things that were previously unimaginable,” Dudchenko added.
By comparing the gene activity of the woolly mammoth with that of an elephant today, scientists can identify genetic differences, thereby advancing efforts to revive this extinct species.
The research was published in the journal Cell.
