A groundbreaking study has mapped the genome and 3D chromosomal structures of a 52,000-year-old woolly mammoth, marking the first such achievement for any ancient DNA sample. Presented in the journal Cell, this work provides deep insights into the organization and activity of the mammoth’s genes. The research owes its success to the exceptional preservation of the DNA, which remained intact due to the mammoth undergoing freeze-drying shortly after death.
Led by Erez Lieberman Aiden of Baylor College of Medicine, the study involved extracting DNA from a well-preserved woolly mammoth excavated in Siberia in 2018. Using Hi-C technology, which detects spatial proximities within DNA, the team created a detailed map of the mammoth’s genome, revealing it had 28 chromosomes, similar to present-day elephants. The DNA’s physical integrity, including nanoscale loops, allowed researchers to identify active and inactive genes in the mammoth’s skin cells, shedding light on its adaptations to cold environments.
Marc A. Marti-Renom from the Centre Nacional d’Anàlisi Genòmica compared the process to solving a complex puzzle without a reference picture, with Hi-C providing a crucial approximation of the final image. Combining this data with DNA sequencing, the team reconstructed the mammoth’s genomic architecture, noting significant similarities and differences with modern elephants, particularly in genes related to its woolly coat and cold tolerance.
This study is not only a milestone in ancient DNA research but also suggests potential applications for studying other well-preserved specimens, from mammoths to Egyptian mummies. The findings may also influence ongoing efforts in woolly mammoth de-extinction. Future research aims to explore the epigenetic patterns of other tissues, further unraveling the genetic secrets of ancient life forms.