What Clues Does Your Dogs Spit Hold For Human Mental Health?

Dogs were the first animals people domesticated, long before a very early human civilizations appeared. Today, tens of thousands of years later, dogs have an remarkably close relationship with us. They share our homes and steal our hearts and have even evolved to love us back. Sadly, they also suffer from many of the same difficult-to-treat psychiatric and neurological diseases we do.

Beskow, in fine spirits. Elinor Karlsson, CC BY-ND

I learned this firsthand about six years ago, when my sister Adria adopted Beskow, a beautiful, boisterous, black and white mutt. Beskow became my constant companion on my morning runs along the Charles River. Her joy in operating was obvious to everyone we passed, and she kept me running mile after mile.

When not operating, though, Beskow suffered from constant nervousnes that left her stressed and unhappy on edge around other dogs and prone to aggressive behaviour. Beskow had trouble even playing outdoors, since she was compelled to attend to every sound and movement. Working one-on-one with skilled behaviorists and trainers helped vastly, but poor Beskow still never seemed able to relax. Eventually, Adria blended the intensive develop with medication, which eventually seemed to give Beskow some relief.

Beskows personality her intelligence, her focus and her nervousnes was shaped not only by her own life experiences, but by thousands of years of evolution. Have you ever known a dog who would retrieve the same ball over and over again, for hours on end? Or simply wouldnt stay out of the water? Or wasnt interested in balls, or water, but just wanted to follow her snout? These dogs are the result of hundreds of generations of artificial selection by human beings. By favoring useful behaviours when breeding dogs, we made the genetic changes responsible more common in their gene pool.

When a particular genetic change rapidly rises in prevalence in its own population, it leaves a signature of selection that we can see by sequencing the DNA of many individuals from the population. Basically, around a selected gene, we find a region of the genome where one particular pattern of DNA the variant linked to the preferred version of the gene is far more common than any of the alternative patterns. The stronger the selection, “the worlds biggest” this region, and the easier it is to see this signature of selection.

In dogs, genes shaping behaviours intentionally bred by humans are marked with large signatures of selection. Its a little bit like evolution is shining a spotlight on parts of the dog genome and saying, Look here for interesting stuff! To figure out exactly how a particular gene influences a dogs behaviour or health, though, we need lots more information.

To try to unravel these connects, my colleagues and I are launching a new citizen science research project were calling Darwins Dogs. Together with animal behaviour experts, weve put together a series of short surveys about everything from diet( does your dog eat grass ?) to behavior( is your dog a foot sitter ?) to personality( is your dog aloof or friendly ?).

Any dog can participate in Darwins Dogs, including purebred dogs, mixed breed dogs, and mutts of no particular breed our studys participants will be very genetically diverse. Were blending new DNA sequencing technology, which can give us much more genetic information from each dog, with powerful new analysis methods that they are able control for diverse pedigree. By including all dogs, we hope to be able to do much larger examines, and home in rapidly on the important genes and genetic variants.

A beagle considers building the saliva donation. Stephen Schaffner, CC BY-ND

Once an owner has filled out the survey, theres a second, crucial step. We send an easy-to-use kit to collect a small dog saliva sample we can use for DNA analysis. Theres no expense, and well share any information we find.

Our plan is to combine the genetic data regarding many dogs and look for changes in DNA that correlated with particular behaviours. It wont be easy to match up DNA with an obsession with tennis balls, for instance. Behavior is a complex trait that relies on many genes. Simple Mendelian traits, like Beskows black and white coat, are controlled by a single gene which determines the observable characteristic. This various kinds of inherited trait is comparatively easy to map. Complex traits, on the other hand, may be shaped by tens or even hundreds of different genetic changes, each of which on its own only slightly alters the individual carrying it.

Adding to the intricacy, surrounding often plays a big role. For example, Beskow may not have been as anxious if shed lived with Adria from puppyhood, even though her genetics would be unchanged.

Darwins Dogs squad member Jesse McClure extracts DNA from a sample. Elinor Karlsson, CC BY-ND

To succeed, we need a lot of dogs to sign up. Initially, were aiming to enroll 5,000 dogs. If successful, well keep growing. With bigger sample sizes, well be able to tackle even more complex biological puzzles.

This is a huge effort, but could offer huge rewards. By figuring out how a genetic change leads to a change in behaviour, we can decipher neural pathways involved in psychiatric and neurological diseases shared between people and dogs. We already know these include not just nervousnes, but also PTSD, OCD, autism spectrum disorders, phobias, narcolepsia, epilepsy, dementia and Alzheimers disease.

Understanding the biology underlying a disease is the first step in developing more effective therapies of both the canine and human assortment. For example, genetic examines of narcolepsy in Doberman pinschers received the gene mutation causing the disease but only in this one dog population. Researching the genes function, though, led to critical new insights into the molecular biology of sleep, and, eventually, to new treatment options for people suffering from this debilitating disease.

Darwins Dogs is analyse normal canine behaviours as well as diseases. We hypothesize that procuring the small genetic changes that led to complex behaviours, like retrieving, or even personality characteristics, like playfulness, will help us figure out how brains work. We need this mechanistic understanding to design new, safe and more effective therapies for psychiatric diseases.

Beskow with one of her loving family members. Adria Karlsson, CC BY-ND

And Beskow? Six years later, she is as wonderful as ever. While still anxious some of the time, the medication and training have paid off, and she enjoys her daily walkings, training and playtime. She still gets very nervous around other dogs, but is a gentle, playful companion for my sisters three young children.

We are now sequencing her genome. In the next few months, we should have our first glimpse into Beskows ancestry. We know she is a natural herder, so were curious to find out how much her genome matches up to herding breeds, and which genes are in that part of the genome.

Of course, we cant figure out much from simply one dog if you are a dog proprietor, please enroll your dog today!

Elinor Karlsson, Assistant Professor of Bioinformatics and Integrative Biology, University of Massachusetts Medical School

Read more: www.iflscience.com

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