Genetic tweak hints at why mammoths loved the cold

Woolly mammoths

Woolly mammoths were fat, hairy and could tolerate extreme cold. Now researchers have tracked down some molecular changes that contributed to those adaptations.

Courtesy of Giant Screen Films © 2012 D3D Ice Age, LLC

A single genetic change may have made woolly mammoths fat, hairy and cold-loving.

Researchers deciphered the genomes of two woolly mammoths that died about 20,000 and 60,000 years ago. When comparing the mammoths’ DNA to that from three Asian elephants, researchers noted that mammoths had different forms of some proteins involved in sensing temperature.

The team produced one of the mammoth temperature sensors, a protein called TRPV3, in the lab. As computer models had predicted, the protein was 20 percent less active than the elephant version, researchers report July 2 in Cell Reports. Mice that lack that protein prefer cooler temperatures and have more fat than usual. They also have curly whiskers and wavy hair. Reduced activity of TRPV3 may have allowed mammoths to tolerate the cold, pack on fat and grow more hair.

“My wild speculation is that they actually liked the cold,” says coauthor Vincent Lynch, an evolutionary geneticist at the University of Chicago. 

Tina Hesman Saey is the senior staff writer and reports on molecular biology. She has a Ph.D. in molecular genetics from Washington University in St. Louis and a master’s degree in science journalism from Boston University.

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