Genetic Clues to How Dogs Became Man’s Best Friend

Sable colored Siberian Husky. 1 credit: Pharaoh Hound

Two mutations in the melanocortin 2 receptor gene, involved in the production of the stress hormone cortisol, may have played a role in the domestication of dogs by allowing them to develop social cognitive skills in order to interact and communicate with humans. The findings are published in Scientific reports.

Changes in different genes, usually controlling hormones that influence social behavior, have been implicated in the domestication of dogs, but it has not been established exactly what genetic changes might have taken place.

Miho Nagasawa and his colleagues studied the social cognitive interactions of 624 domestic dogs using two tasks. In the first task, the dog had to decide which bowl contained hidden food based on cues, such as looking, pointing and tapping, from the experimenters. This tested the dog’s understanding of human gestures and communication. In the second task, the dog was presented with a problem-solving test, which involved them trying to open a container in order to access food. In this task, the frequency and duration of time spent by the dog staring at the experimenters was measured, which represented social attachment to humans. The authors separated the dogs into two groups based on their breed: the Ancient group (consisting of breeds considered genetically closer to wolves such as the Akita and the Siberian Husky) and the General group (all other breeds genetically more distant Wolves). The authors report that the dogs in the elder group looked at the experimenters less often than the other dogs during the problem-solving task, suggesting that they were less attached to humans. There were no significant race-related differences in the first task.

The authors then searched for differences in genes associated with human-related cognitive abilities between the ancient and general groups, including oxytocin (OT) genes, oxytocin receptor (OTR), oxytocin receptor (OTR), melanocortin 2 (MC2R) and a gene called WBSCR17 which is involved in Williams-Beuren syndrome (characterized by hypersocial behavior) in humans. Two changes in the MC2R gene were associated with both correctly interpreting gestures in the first task and looking at experimenters more often in the problem-solving task.

The authors suggest that these findings imply that MC2R may have played a role in the domestication of dogs, perhaps by promoting lower stress levels around humans.

Republished with kind permission from Scientific Reports.

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