Could your dog be prone to a fatal disease? Is your new shelter pup part beagle or boxer? Many pet owners seek answers to these questions, and as a result, direct-to-consumer dog DNA testing is booming.
Human interfering with dog DNA has long been the driving factor behind dogs’ breed diversity — or lack thereof. But a dog’s DNA can also be used to confirm their lineage (血统) or identify their breed, a boon for pet owners on the lookout for breed-specific health or behavioral challenges or those looking to confirm their dog really has the heritage claimed by a breeder or seller. During DNA analysis, labs sequence the dog’s DNA and look for similarities with a dataset of identified dog breeds.
But breed identification isn’t as simple as it might seem. In a study published in the Journal of the American Veterinary Medical Association last month, scientists looked into the accuracy of breed prediction in commercially available DNA tests that required a photo of the dog in addition to its DNA sample. The results were mixed, says Casey Greene, a professor who co-authored the study.
“Most tests could accurately distinguish the breed of purebred dogs,” says Greene. But the analysis suggested that some testing companies might rely on the photo more than the dog’s actual genetics — and revealed big differences between companies’ business practices and the genetic datasets they use to determine dog breeds.
The researchers submitted photos and DNA of 12 purebred dogs to a total of six commercial canine (犬的) ancestry identification services. Since each pup was purebred and possessed extensive American Kennel Club paperwork, the researchers knew their breed conclusively—but in some cases they provided a photo of a different dog to see if the photo influenced the DNA results. One of the companies misidentified a purebred Chinese crested dog — almost entirely hairless — as a long-haired Brittany spaniel, seemingly based on the photo alone. The other five did identify the registered breed correctly, but often gave different predictions for other “ancestor” breeds in dogs whose DNA suggested mixed breeding in prior generations. The researchers concluded that veterinarians and pet owners alike should “approach direct-to-consumer tests with caution” given the lack of industry standardization and at least one company’s reliance on photographs instead of DNA analysis.
Despite these concerns, though. dog DNA seems headed for a golden age — and the insights revealed through further study of Fido’s genome (基因组) have already reached far beyond the doghouse. Domesticated dogs have emerged as surprising superstars in medical research that benefits humans. According to researchers, that’s just the beginning. With implications ranging from entertaining to consequential, there’s no telling what dog DNA will continue to unleash.
【小题1】The underlined word “boon” in paragraph two is closest in meaning to ________.| A．blessing | B．substitute | C．duty | D．struggle |
| A．it assists in accurately determining the breed a dog belongs to |
| B．it helps to predict whether dogs are subject to certain diseases |
| C．it provides pet owners with insights into dogs’ behavioral challenges |
| D．it sequences the DNA of identified dog breeds to find their similarities |
| A．Photos play a more significant role in identifying a dog’s breed than its actual genetics. |
| B．It is a common phenomenon that the DNA analysis of dogs may yield mixed results. |
| C．Commercial dog DNA tests still have limitations and should be dealt with cautiously. |
| D．Direct-to-consumer tests overshadow DNA analysis in identifying purebred dogs. |
| A．Controversies regarding its reliability are here to stay. |
| B．It is bound to make breakthroughs in the fields of medicine and entertainment. |
| C．It can step into a golden age as long as some research limitations are fixed. |
| D．It may have far-reaching significance and be applied to a wider range of areas. |
