Inuit People Living In The Arctic Are Adapted To Cold, Thanks To Their TBX15 And WARS2 Genes

Scientists carried out a thorough genomic analysis of the Inuit people living in Greenland and discovered two active genes, namely, TBX15 and WARS2, which help them adapt to extreme cold conditions. These genes are responsible for generating body heat by burning fat so that the Inuit people can survive in extreme cold conditions.

Further investigations made by a different team of scientists under Fernando Racimo studied the natural selection of the Inuit people, in order to trace back the origin of these genetic adaptations. They compared the genomic data of 200 Greenlandic Inuit people with the ancient hominid DNA obtained from fossilized Neanderthals and Denisovans. The study revealed that the TBX15 and WARS2 genes were transferred to modern Inuit people from the archaic hominid population. The study was published in the Molecular Biology and Evolution journal.

Fernando Racimo, the lead investigator of the project, said, "The Inuit DNA sequence in this region matches very well with the Denisovan genome, and it is highly differentiated from other present-day human sequences, though we can't discard the possibility that the variant was introduced from another archaic group whose genomes we haven't sampled yet," Phys.org reported.

It was also found that the gene was present in high frequency in the Inuit people and in the Native Americans but is almost absent in the African population. The study also revealed that there were remarkable differences in the methylation patterns of the TBX15 and WARS2 gene region among the Denisovan genome, the Neanderthals and the modern day human beings.

"All this suggests that the introduced variant may have altered the regulation of these genes, thought the exact mechanism by which this occurred remains elusive," Racimo said.

On the basis of these results, the scientists speculated that the presence of this archaic gene variant may have been responsible for the survival of modern men during their expansion to Siberia, Beringia and later into the Americas.