Thaindian News

Washington, Feb 7 (IANS) Black wolves owe their coat to the cousins of the domestic dog, which bred with them thousands of years ago, transferring a gene responsible for the colour. The effect was more than just cosmetic: the resulting black wolves, which are found nearly exclusively in northern America, seem to have a selective advantage over lighter-coloured wolves in forested areas.

It’s a rare instance of domestic animals - in this case, probably the dogs of the earliest Native Americans - contributing to the genetic variability of their wild counterparts in a way that affects both the recipients’ appearance and survival.

“We usually think of domestication as something that is carried out to benefit humans,” said genetics professor Greg Barsh. “So we were really surprised to find that domestic animals can serve as a genetic reservoir that can benefit the natural populations from which they were derived,” he said.

Barsh and graduate student Tovi Anderson collaborated with scientists at the University of California-Los Angeles, University of Calgary, the National Park Service at Yellowstone National Park and the National Human Genome Research Institute to conduct the research. Scientists from Sweden and Italy also participated in the international effort.

Anderson and her collaborators compared DNA collected from 41 black, white and gray wolves in the Canadian Arctic and 224 black and grey wolves in Yellowstone National Park with that of domestic dogs and grey and black coyotes.

“We expected this to be a short research project to confirm that wolves and dogs shared the same genetic pathway that determines black coat colour,” said Anderson. “But the story got much more interesting when we expanded our research and began asking about the origin of the mutation in wolves.”

Barsh’s lab discovered in 2007 that the gene responsible for black fur in dogs, called beta-defensin, belongs to a family of genes previously believed to be involved in fighting infection, said a California release.