A team of researchers at Linköping University in Sweden has identified two genomic regions and five candidate genes associated with dog’s human-directed social behaviors. Interestingly, four of these genes are also related to social behavior disorders in humans.
Dogs are unique among domesticated animals, having been integral parts of human societies for at least 15,000 years.
During the course of domestication they have evolved several social skills enabling them to communicate and cooperate with humans to an extent unmatched by any other species.
In this respect, they are widely superior to their wild ancestors, the wolves. Facing a difficult task, most dogs seek contact with a human, apparently to solicit help. In similar situations, wolves generally attempt to solve the problem themselves.
“Our findings are the first to reveal genes that can have caused the extreme change in social behavior, which has occurred in dogs since they were domesticated,” said lead researcher Prof. Per Jensen, a researcher with the AVIAN Behavior Genomics and Physiology Group at Linköping University.
In their experiments, Prof. Jensen and co-authors wanted to study the behavior of the dogs by presenting them with an unsolvable problem.
“We studied dogs when they were individually presented with an unsolvable problem. The dogs were allowed to manipulate a device where they could easily obtain two treats, but a third had been made inaccessible,” they said.
“This caused most of the dogs, at some point, to turn to the nearby human and seek cooperation by gazing towards the eye region and through physical proximity and contact.”
The team used video recordings to quantify the willingness of the dogs to seek physical contact with a nearby person. 437 laboratory beagles with similar earlier experiences of human interactions were part of the behavioral studies. For 190 individuals the DNA was studied.
By using a method called GWAS, the researchers examined a large number of genetic variants throughout the genome. It turned out that the contact seeking dogs more often carried certain genetic variants.
“We found a clear association with DNA-regions containing five different interesting genes (SEZ6L, ARVCF, TXNRD2, COMT and TANGO2),” said team member Mia Persson, also from the AVIAN Behavior Genomics and Physiology Group at Linköping University.
“Four of the genes are known from studies of social disorders in humans, for example, autism and attention-deficit hyperactivity disorder (ADHD).”
“If the associations we have found can be confirmed in other dog breeds it is possible that dog behavior also can help us to better understand social disorders in humans,” Prof. Jensen added.
The team’s findings were published in the journal Scientific Reports on September 29, 2016.
M.E. Persson et al. 2016. Genomic Regions Associated With Interspecies Communication in Dogs Contain Genes Related to Human Social Disorders. Sci. Rep. 6: 33439; doi: 10.1038/srep33439