Gene linked to autism in people may influence dog sociability

Published by Théophile Niyitegeka
On 3 October 2016 saa 01:15
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DNA differences affect beagles’ tendency to seek human help.

Dogs may look to humans for help in solving impossible tasks thanks to some genes previously linked to social disorders in people.

Beagles with particular variants in a gene associated with autism were more likely to sidle up to and make physical contact with a human stranger, researchers report September 29 in Scientific Reports.

That gene, SEZ6L, is one of five genes in a particular stretch of beagle DNA associated with sociability in the dogs, animal behaviorist Per Jensen and colleagues at Linköping University in Sweden say. Versions of four of those five genes have been linked to human social disorders such as autism, schizophrenia and aggression.

“What we figure has been going on here is that there are genetic variants that tend to make dogs more sociable and these variants have been selected during domestication,” Jensen says.

But other researchers say the results are preliminary and need to be confirmed by looking at other dog breeds. Previous genetic studies of dog domestication have not implicated these genes. But, says evolutionary geneticist Bridgett vonHoldt of Princeton University, genes that influence sociability are “not an unlikely target for domestication — as humans, we would be most interested in a protodog that was interested in spending time with humans.”

Most dog studies take DNA samples from pets or village dogs and wild wolves. Jensen’s team instead studied beagles that had been raised in a lab. None of the dogs had been trained. To test sociability, the researchers gave the dogs an unsolvable problem in a room with a female human observer whom the beagles had never seen before. The puzzle was a device with three treats that the dogs could see and smell under sliding lids. One lid was sealed shut and could not be opened.

After opening two lids, the dogs “get very confident that this is not a difficult task, but then they encounter the third lid and that’s where the problem gets impossible,” Jensen says. Wolves would have kept trying to solve the problem on their own (SN: 10/17/15, p. 10). But after some futile attempts, many of the beagles looked to the human observer for help. Some dogs tried to catch her eye, glancing back and forth between the woman and the stuck lid. Other dogs made physical contact with or just tried to stay to close to the woman.

The researchers then looked for places in the dogs’ DNA where the most and least human-friendly dogs differed. A region on chromosome 26 kept popping up, indicating that genes in that region could be involved in social interactions with people.

The finding is a statistical signal, but doesn’t establish what the genes might be doing to influence the dogs’ behavior, says Adam Freedman, an evolutionary geneticist at Harvard University. And since the researchers only examined the beagles, it’s not clear that the same genes would affect behavior in other dogs, he says.

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Beagles that encountered an impossible problem — an immovable lid covering a treat (shown) — sometimes sought help from a nearby human stranger. Variations in a gene previously linked to autism in humans may influence the dogs’ people-seeking behavior.