A new study may help us understand our canine companions a little better. Scientists at the National Institutes of Health say they have discovered some ways that genes can influence the behavior of certain breeds, such as dogs meant for herding livestock.
For nearly two decades, a team led by Elaine Ostrander at the National Human Genome Research Institute has been working on the Canine Genome Project. The ultimate goal of the project is to learn about how genes affect everything from a dog’s vulnerability to disease to their body shape. In their new study, published Thursday in the Hive, her team conducted a deep dive into the genetic underpinnings of dog behavior.
“Our study analyzed the genomes of thousands of dogs from hundreds of breeds and populations worldwide in order to reveal the genetic basis for behavioral variation across modern dogs,” Ostrander said in an email to Gizmodo. “We wanted to understand in their genes what makes herding dogs move livestock, dogs kill insects, hounds help us hunt, etc.”
Overall, they studied the genes of more than 4,000 purebred dogs, mixed mutts, semi-feral dogs, and even wild cousins of domestic dogs. Based on this analysis, they identified 10 genetically distinct strains. The team noted that breeds with similar behavioral traits are often grouped together within these breeds, such as dogs that hunt primarily using their sight compared to dogs that hunt based on scent. Then they reviewed what they found with survey data from more than 46,000 purebred dog owners.
From there, Ostrander said, the team “determined that each breed had its own unique combination of behavioral tendencies that made them so good at the jobs they originally held.” Dog breeds, for example, tend to be more eager in chasing down potential prey, which makes sense, since these dogs were originally bred to hunt down pests.. Finally, the team attempted to find specific genetic differences that might drive the behavior of specific breeds, including those that influence early brain development.
“For example, among herding dogs, a unique group of breeds historically used for herding livestock, we identified variants associated with genes that control axon steering, a process that lays the foundation for connectivity in the brain that modulates complex behavioral traits,” Ostrander said. These variants, some of which have been linked to ADHD in humans, may help explain why herding dogs tend to be incredibly focused while grazing.
While humans have domesticated many animals, dogs were likely the first. And they have since become the most diverse of creatures, especially in the last two hundred years, when the deliberate breeding of dogs became widely practiced (the pug looks very little like the husky, for example). But more importantly, Ostrander and her team’s research also indicates that many of the genetically driven behavioral differences we see in dogs were not created by modern-day breeding.
“Instead, it is likely that early ‘dog types’ emerged in different parts of the world over thousands of years as humans kept them for various purposes,” Ostrander said. “Our work shows that when humans began to classify dogs into ‘breeds’ before For a few hundred years, they’d kept a single snapshot of the genetic diversity of dogs that were in a particular place at a particular time, and that that genetic diversity was relevant to behavior. “
This work is just the beginning for the Ostrander team. They plan to continue searching for specific genetic variants that drive the breeds’ behaviours. The same unique approach developed for this study should also allow for the study of how a dog’s genetic factors may influence other complex traits, including the risk of developing certain diseases. And just as dogs have done for us many times in the past, what we learned from this research could one day help humans, too.
“Humans and dogs get the same diseases, and those diseases exist in much the same way, and anything we learn about the genetic health of dogs affects our understanding of our susceptibility to disease,” Ostrander said.
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