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A CANINE FAMILY CIRCLE

A FAMILY CIRCLE that was developed at the National Human Genome Research Institute has been called a tour-de-force of Canine lupus familiaris evolution. The most extensive research of its kind to date, the study analyzed 150,000 points of DNA data from each of 1346 dogs representing 161 breeds around the world. Veterinarians benefit from such data in identifying why some breeds are more susceptible to specific health problems than others. Also, the study of other mammals, especially canines, enhances the understanding of human genetics.

The National Human Genome Research Institute, headquartered in Bethesda, Maryland, is one of 27 institutes and centers making up the National Institutes of Health. NHGRI was established in 1989 as part of an International Human Genome Project. Completion of the human genome sequence came in 2003. Since then, the institute’s continued research has included a Cancer Genome Atlas and a Genomic Medicine Working Group.

A related paper describes why NHGRI would get involved specifically with canine research: The summary in “Sequencing the Genome of the Domestic Dog Canis familiaris notes “The dog enjoys a genetic diversity unrivaled by any other mammalian species. A thousand centuries of directed breeding by humans has channeled that diversity into an unequaled variety of morphologies and behaviors, and also into a storehouse of inherited diseases. The availability of a high-quality genome sequence and associated SNP [single nucleotide polymorphisms, variations in DNA building blocks] map would provide the key allowing us to exploit that genetic heritage to advance our understanding of normal biology and disease of both dogs and man.”

In Science magazine, April 25, 2017, Elizabeth Pennisi writes, “Where Did Your Dog Come From? New Tree of Breeds May Hold the Answer.” She amplifies on canine genetic diversity by noting that Great Danes grow to 175 lb., Teacup Poodles weigh perhaps 2 lb., yet they are both members of the same subspecies, Canis lupus familiaris.

A family circle of dogs. The circled and starred links indicate percentages of DNA concurrence. Image from Science, April 25, 2017.

Pennisi writes of the canine family: “Almost all the breeds fell into 23 larger groupings called clades…. Although genetically defined, the clades also tended to bring together dogs with similar traits.” Those bred for strength, boxers and bulldogs, for instance, fall into one clade; herder dogs, into another; hunters, into a third.

“But,” Pennesi observes, “the data also show how some breeds helped create others, as they share DNA with multiple clades. … the pug, which hailed from China, was used in Europe from the 1500s onward to shrink other breeds. Thus, pug DNA is part of many other toy and small dog genomes.”

Another discovery involved a genetic disease called Collie Eye Anomaly. Vets recognized that this disease showed up in Collies and Australian Shepherds, yet also surprisingly in Nova Scotia Duck Tolling Retrievers. Researchers conjecture that, somewhere in the Nova Scotia dog’s heritage, it picked up the damaged gene from either a Collie or an Australian Shepherd ancestor.

It’s also interesting to find your favorite pooch in the canine family circle and identify unexpected relatives. For instance, Kenwood, our Husky/Malamute, had obvious kinship with other breeds of Eastern Asia, the Chow and Akita; but also with the Greenland Sledge Dog. And what about the Peruvian Hairless, Chinook and German Shepherd? This sounds like something worth sniffing out. ds

© Dennis Simanaitis, SimanaitisSays.com, 2017

One comment on “A CANINE FAMILY CIRCLE

  1. carmacarcounselor
    May 10, 2017

    Most surprising result for me is that the German Shepherd and Belgian Malinois are so far apart on the chart – six “cledes” removed.

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