Twenty-eight years ago, Elaine Ostrander set out to map dog genomes. The genetics researcher wanted to understand why dogs behave how they do and what in their genes might determine that. She knew this type of mapping was possible; two contemporary studies had shown that much. What she didn’t know was that it would take a quarter-century and dozens of studies for her team to find an answer.

Now, Ostrander leads the Dog Genome Project, an initiative she launched in 2004 in conjunction with the National Institutes of Health. But the project’s research goals aren’t just to learn about our best friends. Scientists want to discover new things about humans, too, which is why the NIH has taken an interest in our four-legged friends. It turns out humans and dogs are remarkably similar genetically, and studying our canine companions can help us learn more about diseases in humans.  

“Humans are really hard to work with,” says Elinor Karlsson, professor at the UMass Chan Medical School and founder of Darwin’s Ark, a citizen science project to collect genetic information about pets. “But dogs don’t live as long, so if you want to study aging or cancer, you can do it on a faster timescale.” What’s especially important about dogs, she adds, is that they live with us. “If you’re worried about the interaction between genes and the environment for things like cancer,” she says, “you can actually test that interaction by studying dogs.”

But the Dog Genome Project isn’t just studying dogs for humanity’s sake. It’s also working to understand canines better. In a study published earlier in December, Ostrander and her team finally unlocked one piece of the puzzle: Can genes determine what dogs are good at? Yes. 

“When you look at dogs at the dog park, and you recognize their breed, you have certain expectations for how they’re going to behave in a certain situation,” Ostrander says. “If it’s a border collie, we expect it to herd sheep; if it’s certain kinds of terriers, we expect it to be a ratter.” But instead of relying on those preconceived expectations of how humans think dogs should act, the researchers looked at genes. Using the genomes of “thousands and thousands of dogs,” she says, the researchers could establish each breed in a “lineage” of shared behavior.

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With the genetic data from more than 4,000 dogs as well as behavioral survey data of more than 40,000 dogs from pet owners, the team was able to identify 10 lineages among the hundreds of studied breeds. Each of these lineages corresponded to a historic use of breeds, such as herders and retrievers. When combined with the behavioral information submitted by pet owners, the researchers saw unique behaviors associated with each lineage. 

“Because we needed them to hunt, we needed them to herd, we needed them to guard our flocks, we needed them to guard ourselves,” Ostrander says, “we’ve been selecting to get these ever more refined behaviors.” For herding dogs, for instance, the scientists identified a class of genes that Ostrander says “looks like it’s been under a really strong selection by humans” to produce shepherd-like behavior.  

The National Institutes of Health is studying dogs to learn more about aging and genetics in people
National Institutes of Health staff scientist Dayna L. Dreger swabs her dog, Gio, to take genetic samples. Dayna L. Dreger

“When I came to NIH, I really, really wanted to solve morphology problems,” Ostrander says. “How many genes does it take to make a Great Dane versus a Chihuahua? It takes less than 30. In humans, the difference between being 5’6” and 6’6”, that’s over 1000” gene locations, she says, “Humans have had millions and millions of years for nature to tweak this and tweak that. Dogs haven’t had that long.” 

Most dog breeds have only been around for a few hundred years, which is “nothing in terms of evolution,” Ostrander says. In other words, studying dogs is “like looking at a movie and fast-forwarding to get to the end,” she says. Learning how nature has shaped these animals so quickly “would inform studies of diversity across all species, and all mammals,” she says.

Since Ostrander set out to study dogs nearly three decades ago, numerous breakthroughs have happened, from understanding dog size to publishing the first map of the dog genome. “That threw everything wide open,” Ostrander says, and has set a foundation for her subsequent work at the NIH.

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One of the project’s biggest accomplishments was the 2007 discovery of the genes that determine dog size. “That was huge,” Ostrander says. “I remember the day that that postdoc walked into my office and said, ‘You’re not going to believe this.’ And I said, ‘Do it again, do it again, do it again, over and over.’ And it was real, and it’s been validated by hundreds of labs.”

But despite our similarities to our four-legged companions, making the leap from a citizen-science-based dog project like Ostrander’s to helping humans isn’t always easy or immediate. “It’s a long way to go from a genetic study to a therapeutic, but anything that might give you a new direction to explore in terms of developing a therapeutic is going to be of interest,” says Karlsson.

Still, beyond helping dogs, Ostrander has already seen her work have an impact on human health, guiding research in places as diverse as an epilepsy lab in Minnesota and a lupus lab in France. “That’s of tremendous value, because all those things reflect back on humans,” she says. “From the same genes, the same diseases, the same presentation, to the same response to therapies, humans and dogs are still best friends.”