The Himalayan marmot (Marmota himalayana) has always fascinated scientists and alpinists who travel to high altitudes.
The large squirrels dwell at elevations of 1,900–5,000 m around the Himalayan regions of India, Nepal, and Pakistan, and the Qinghai-Tibetan Plateau of China. At such altitudes, the air is thin and temperatures regularly plummet to below zero degree Celsius. But, these squirrels continue to thrive under such resource-scarce conditions.
Scientists studying the genetics of the ‘beaver-ish rodents of unusual size’ may have found an answer. Researchers from Jiaotong University Health Science Center in China, who assembled a complete draft genome of the animal, believe that the animal managed to thrive not just because the rodents hide in burrows some 30 feet deep for more than six months during the winter, but also because their genes mutated some two million years ago.
“As one of the highest-altitude-dwelling mammals, the Himalayan marmot is chronically exposed to cold temperature, hypoxia [lack of oxygen], and intense UV radiation,” Enqi Liu of Xi’an, the lead author of the paper, said in a statement.
When the researchers compared the Himalayan marmot’s genome to four other marmot species, it was found the Himalayan marmot’s line split from that of its closest relative rodent about 2 million years ago. The researchers, who compared the genomes of Himalayan marmots with genomes of Himalayan marmots that live at a much lower elevation, the difference was more significant. One gene, in particular, stood out from the rest.
According to the paper, Himalayan marmots that thrive in resource-scarce areas may have a mutation in a gene called Slc25a14. The researchers found that although other mammals such as mice, bonobos and other marmots, have one version of the gene, high-altitude-dwelling marmots have another version that may give them special abilities to survive in extreme cold.
The gene is believed to help control the function of mitochondria, the cell’s powerhouses. It is also believed it that has neuroprotective effects and plays a role in maintaining metabolism as well as temperature regulation–critical for animals living in the ‘Third Pole’. The researchers have a hunch that the genetic change may have helped the marmots adapt to their home in the Himalayas.
The finding could have implications for human health, argues Liu. The authors of the paper say that now that the distinctive genetic trait has been identified, this knowledge could be used to improve human adaptation in high altitudes.
