Woolly mammoth DNA, frozen for 52,000 years, may aid in species revival
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Scientists have made a groundbreaking discovery with a 52,000-year-old woolly mammoth hide, remarkably preserved in Siberia's frigid conditions, enabling the reconstruction of the animal's genome in three dimensions.
This significant breakthrough, detailed in a study published in the journal Cell, could provide vital insights into extinct species and potentially aid in their revival.
Previously, ancient DNA specimens were only found in short, fragmented pieces, limiting researchers' ability to extract comprehensive information. However, the new study demonstrates that under certain conditions, the original arrangement of DNA can be preserved.
Co-author Olga Dudchenko, a geneticist at Baylor College of Medicine, emphasized that this discovery shows the potential for preserving the 3D architecture of an organism's genome.
Understanding the 3D structure of a genome is crucial for identifying gene activity in specific tissues, which explains various cellular functions such as brain activity, heartbeats, and immune responses. Until now, it was believed that such detailed genetic information could not survive the rapid degradation over millennia.
A decade-long search led an international team to an exceptionally well-preserved woolly mammoth sample, excavated in northeastern Siberia in 2018. This specimen, a female with a distinctive mullet-style hairdo, was likely skinned by early humans, leaving some tissue intact. The skin's transition into a glasslike state preserved the DNA's structure, essentially creating a piece of freeze-dried woolly mammoth jerky.
To validate their findings, the researchers subjected both lab-made and store-bought beef jerky to various tests simulating ancient sample damage. Despite the jerky breaking into tiny bits, the chromosomes remained intact at a nano-scale. This resilience demonstrated the potential for preserving DNA structures over long periods.
One significant discovery from their research established that mammoths had 28 pairs of chromosomes, aligning with the 28 pairs found in elephants, their closest living relatives. This was previously unknown. Additionally, the study identified genes that may have contributed to the woolly mammoth's distinctive features, such as long, thick eyelashes and sparse sweat glands.
Although the primary goal of the research was not to revive mammoths, the findings could contribute to de-extinction efforts. In Japan, a team is exploring cloning woolly mammoths, while in the United States, researchers aim to create genetically "mammothized" elephants.
The study opens new possibilities in paleogenetics, suggesting that similar "fossil chromosomes" could be found in the Arctic permafrost or through mummification in warmer climates.
