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Can DNA Decipher the Mix?

How They Do It
Sue DeNise, vice president of genomic research at MMI Genomics Inc., which developed the Canine Heritage Breed Test specifically for mixed-breed analysis, talked to us about how her company analyzes canine DNA. “We’ve been doing testing for AKC parentage verification for a long time,” she notes. “We initially started working in the cattle business, looking for genetic markers in order to trace what was important to cattle breeders. Out of that whole-genome association study, we had purebred and crossbred cattle, so we asked, ‘What can the markers tell us about underlying traits in breeds of cattle?’” Their discovery paved the way for the companion animal program, which was modeled on what they learned with cattle.

“We look at ’breedness‘ among dogs. Our canine database is built with 10,000 samples of 108 breeds. We ran 400 markers to identify the best markers for a ’breedness‘ test against 38 breeds. We created a panel of 96 pieces of DNA that split dogs into their identified pure breed. In our preliminary test, we found that individual purebred dogs cluster with other purebreds.” Initially, MMI chose 38 AKC registered breeds from their database, selected for their popularity based on number of registrations. Recently, as DeNise notes, they increased the number to 108 breeds. This jump in breed recognition required testing thousands of markers to identify the just over 300 markers that characterize these 108 breeds.

Constructing Breeds
Like all species, domestic dogs are on an evolutionary journey, starting at wolf and going somewhere yet to be determined. We tinker with evolution, but might be surprised to find out we don’t control it. Our concept of a breed—that individuals within the breed look alike—is nothing more than a snapshot of the DNA time line, taken while we’re doing the tinkering.

Breeds are created a number of ways. In simple terms, when breeders interfere with natural reproduction and rigorously select for traits favored by humans, specialized breeds like Retrievers, Spaniels, Hounds and Terriers are the result. Saving spontaneous mutations in a litter of dogs, repeating the breeding to get more of the same mutation, and breeding those dogs back to one another has resulted in the English Bulldog, Chinese Crested and Inca Hairless. More recent breeds, such as the Airedale, Australian Cattle Dog and Doberman, are the result of crossing older breeds to make new ones.

When kennel clubs closed gene pools in the late 19th century to suspend change in registered dogs, breeds drifted toward a more uniform stereotype. Until the early 1800s, an assortment of dogs with similar talents who could produce somewhat similar offspring were awarded the right be called a breed. Breeds evolved, flourished and disappeared when jobs were eliminated. Tumblers, who mesmerized prey by “winding their bodies about circularly, and then fiercely and violently venturing on the beast,” disappeared when guns came into widespread use. Turnspit dogs, who made a living running on a wheel to turn meat so it would cook evenly, received their pink slips when technology improved cooking methods.

By and large, Victorian society was not so pragmatic; sentimentality and commercial opportunity were catalysts for saving unemployed breeds from their inevitable demise. As a result, many Terrier breeds went from killing varmints in the barnyard to killing time in the Victorian parlor in less than a decade.

Whereas previously, a breed was a regional product maintained and preserved by a small community of knowledgeable people, commercial interest in the well-bred pet dog initiated a shift in breeding practices during the Victorian era. The old-money kennels operated as a pastime by the wealthy gave way to a large number of small, commercially operated kennels run by entrepreneurs of modest means and experience.

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Submitted by Anonymous | August 4 2011 |

Fascinating. So are DNA tests accurate enough to be useful in identifying the breeds in your mutt?

Submitted by Dave Strack | February 5 2013 |

I am still a skeptic as to the accuracy of these tests. There have been results that have been documented in which the same dog's sample was submitted to the same lab twice with entirely different results, dogs with color patterns and coat types that have been studied to identify the specific genes needed to produce them but the DNA test did not identify any breeds in the test result that could have produced the dog being tested, and an unscientific report of a test on ans 8 pound dog that listed only large breeds in its ancestry (a little white Rottweiler?).
The DNA testing is not one where a sample is put into a machine that spits out the answers. A human still has to interpret the raw result to come up with the answers - can you say human error. If you are just curious go ahead and have your dog tested. I would not like to think of a situation where my dog's life depended on these test results.

Submitted by Jane Brackman | March 28 2014 |

Read a more recent article I wrote about DNA tests, published in Bark in December 2012. http://thebark.com/content/do-dna-tests-reveal-genetic-secrets
You still may be a skeptic, but you'll have more knowledge about why the tests are accurate but appear contrary to what we see in our mixes.

Submitted by Lorri | October 20 2011 |

Thank you Jane Brackman for this article. It was very informative and interesting. I'd love to know what has transpired, since it's been three years since the article was published in The Bark.

Submitted by Jane | March 1 2012 |

That's the same thing I've been asking myself Lorri. And yes, I'm working on an updated piece. I've been sending my mixed breed pooches DNA into two companies to see if the results are the same.

Submitted by Kathi | July 30 2012 |

Jane,

I have been doing my own research on the various DNA tests plus DNA breed identification. This is because my city has a breed ban on certain breeds of dogs. I am not a scientist:( which makes this difficult. Mars Wisdom Panel is the only test that is available now to my knowledge. The shelter at our city has been testing questionable mixed breeds since 2009 with the Wisdom Panel Professional. We've done 20+ dogs so far. We have even done both test(Insight & Professional)on the same dog to see if we received the same results (we did). Our city does not acknowledge DNA testing but the city council is open on us gathering information (with the city) to determine if DNA testing can determine the banned breeds. Our city will accept the banned breeds if they are less than 50% of the banned breeds. This is currently determined by animal control officers visual identification. When will your updated piece be out? I'll be looking forward to it.

Submitted by Mia | November 17 2012 |

It is completely cruel and just plain wrong to ban an entire breed of dog. The dog is what you bring it up to be. PEOPLE are the ones that should be punished for TEACHING the dog to fight or be cruel or purposely inbreeding....Jail time and permanently keeping animal cruelty on their records should be put into law!

I have recently gotten a pitt bull mix (weimeraner we think) but he has fit right in! And is the most loving dog....I have six dogs and the lab/labradoodles that we have are more aggressive than he is - Especially with strangers walking in front of the house or people coming in....

Banned breeds should be banned people - people are the ones that are cruel.

Submitted by Anonymous | February 4 2013 |

I agreed to watch a friend's pitbull for one night and he moved out of state. So I had this huge brendle 11 year old pit bull, and I was scared of him. I had him for 3 years, and he was one of the most sweetest dogs I ever owned. At first I thought he was mute, he never barked for 3 months until I had him tied up outside and I walked out of his line of sight, that was the first time I ever heard him bark. A drunk friend of mine climbed through my window in the middle of the night and the dog just tackled him and licked him to death. I thought "what a lousy guard dog." But I would take him with me on runs, and a creepy guy approached me and he sensed my unease and went after the guy. He would let babies ride him like a horse. He was a great dog. But I couldn't get renter's insurance because of him.

Submitted by Anonymous | October 27 2011 |

So the "groups" are: Two hounds, MULTIPLE Spitz dogs, and a few small breeds... I think these groupings are messed up. At the very least, Asian Spitz dogs should have been one group (with the exception of the Chow Chow the visual and behavioral similarities are striking.)

Submitted by Erin | April 18 2012 |

Thanks for the interesting article! I had my dog's DNA tested recently and it was an interesting experience to say the least! She came back with about nine different breeds detected! The Humane Society believed her to be an Australian Cattle Dog/mix, however none was detected. They came up with boxer/miniature schnauzer mixed with a keeshond/chow chow. We really just did it for fun and it was affordable (around $60), but it might be interesting to see if the other companies that offer this service would come up with similar results. I am looking forward to reading your follow-up article regarding this. Of course, we love her no matter what the results are!

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