What does the fox say [about human behavior]?

INNOVATIONS]

What does the FOX SAY

[about human behavior]?

You know the look: your furry canine companion cocks his head to the side, wide-eyed but intent. It’s adorable. But it’s also remarkable, if you think about it. This nonhuman creature is actually listening to you, responding. Add to this the wagging, the “smiling,” the (sometimes) obedience, and it’s easy to see how dogs got the reputation as man’s best friends. But how did they get that way?

Dogs evolved from wolves too long ago for scientists to pinpoint exactly how they picked up their friendly behaviors. But in an effort to replicate the process in real time, in 1959 Russian geneticist Dmitriy Belyaev began a long-term experiment to domesticate silver foxes (Vulpes vulpes). He mated the foxes that seemed most tame, and later mated foxes that showed more aggressive behaviors.

After only six generations, some month-old pups were eager for human attention, licking and whimpering when experimenters approached their cages. Today, 58 years after the experiment began, more than 80 percent of the tame group are “elite,” showing extremely friendly behaviors toward humans.

Anna Kukekova, an assistant professor in the Department of Animal Sciences, has been studying the foxes at the Russian Institute of Cytology and Genetics since 2002. For her, the foxes do not simply retell the tale of canine domestication. Rather, they provide a model system to understand the genetic underpinnings of complex social behaviors in mammals, including humans.

The foxes could also help us understand our own responses to stress. “The tame foxes are very stress-resistant,” Kukekova says. “Compared with conventional or aggressive foxes in stress-inducing situations, the tame foxes aren’t stressed at all.”

Jessica Hekman, who recently earned her Ph.D. in Kukekova’s lab, is studying hormonal differences in tame and aggressive foxes. Normally, messages from the brain are translated into hormones that elicit further responses in the body. Hekman’s research shows that this process may function differently in tame foxes and aggressive ones.

Ultimately, the team hopes that understanding the genetic and hormonal basis of behavior in foxes will help in development of medications to modify behavioral disorders in humans.

“Right now, it’s complicated to pair the right medication with the right animal or person. If we could really understand what was going on in the brain, that would help us better figure out how these meds work,” Hekman explains. “I would love it if someday we could do a quick genetic test and say, ‘Prozac is the right medication for this dog or this person,’ or even use what we’ve learned about brain biochemistry to develop new meds.”

By Lauren Quinn

“There are not many models that exist to study complex behaviors, particularly behaviors such as sociability or aggression,” Kukekova says. “Most work is done on fruit flies or mice and looks only at very specific types of aggression. But fox social behavior is more complex than that of rodents, and the behavioral differences in tame and aggressive foxes have significant parallels to social behaviors in humans.”

Those parallels have recently earned Kukekova, along with several collaborators, $1.22 million from the National Institutes of Health to study the foxes. The NIH is interested, Kukekova says, because this research could shed light on human disorders, such as autism, that are characterized by unusual social behaviors.

“Researchers have done genome-wide scans comparing patients with and without autism, but it’s hard to make sense of the results. The work we’ll be doing is aimed to understand the genetic architecture of tame and aggressive behaviors in foxes,” Kukekova says. “The genes that influence these behaviors in foxes may play a role in social behavior of humans as well.”