Is your pooch a herder or a hunter? You can try taking them to a trainer, but new research shows much of their behavior is hardwired in their DNA.
For the new study, researchers analyzed DNA samples from more than 200 dog breeds and surveyed 46,000 pet-owners to try to suss out why certain breeds act the way they do.
“The largest, most successful genetic experiment that humans have ever done is the creation of 350 dog breeds,” said senior study author Elaine Ostrander, founder of the Dog Genome Project at the National Human Genome Research Institute (NHGRI). “We needed dogs to herd, we needed them to guard, we needed them to help us hunt, and our survival was intimately dependent on that.”
But identification of the genes underlying dog behavior has historically been challenging, according to first author Emily Dutrow, postdoctoral fellow at the NHGRI.
The research team gathered whole-genome data from more than 4,000 purebred, mixed-breed and semi-feral dogs, as well as wild canids. (Wild canids are dog-like animals whose features allow them to survive in the wild.)
The findings were published online Dec. 8 in the journal Cell.
The investigators identified 10 major genetic lineages among the hundreds of dog breeds, solely on the basis of DNA data.
Each lineage was part of a specific category of breeds used for certain tasks, including hunting by scent versus sight, or herding versus protecting livestock. An increased drive for prey, for example, was associated with terriers, which contains breeds historically used for catching and killing prey.
This data told researchers that common sets of genes were responsible for behaviors among dog breeds that were well-suited for similar tasks.
“Having established significant behavioral tendencies correlated with the major canine lineages, we then identified genetic drivers of these behaviors by performing a genome-wide association study on the DNA samples,” Dutrow said. “We were particularly interested in livestock-herding dogs, who display one of the most easily defined breed-typical behaviors, characterized by an instinctive herding drive coupled with unique motor patterns that move herds in complex ways.”
The search led researchers to specific genes involved in brain wiring in herding dogs. They discovered that variants near genes involved in axon guidance (a process that shapes brain circuitry) were highly enriched in these dogs. The team also found an enrichment for genes that are important for development of brain areas involved in learned fear responses and social signals.
“When you get a certain input or stimulus, the degree to which that creates a reaction in different parts of the brain shapes how we behave,” Ostrander said. “So, if nerves within and between brain regions don't communicate in specific ways, then the behavior doesn't happen, and this is where axon-guidance genes come into play.”
The researchers also found that genetic variants associated with sheep dogs are often located near genes involved in an axon-guidance process involved in brain development. It plays a role in behavior of other species, too, including humans.
For example, a gene associated with sheep dogs has been associated with human attention-deficit/hyperactivity disorder (ADHD) and anxiety-like behaviors in other animals.
The study authors said these findings could help researchers understand the high energy requirement of sheep dogs and their hyper focus when given a task.
“The same pathways involved in human neurodiversity are implicated in behavioral differences among dog lineages, indicating that the same genetic toolkit may be used in humans and dogs alike,” Dutrow said in a journal news release.
Ostrander said Dutrow's methodology allowed her to capture the different histories of dog breeding around the world, in one approach, one experiment and without prior assumptions.
“After 30 years of trying to understand the genetics of why herding dogs herd, we're finally beginning to unravel the mystery,” she said.
The American Kennel Club has tips for dog behavior training.
SOURCE: Cell, news release, Dec. 8, 2022