DNA testing man's best friend-what is it, why do it and what do the results mean?

摘要

Since the sequencing of the canine genome was completed in 2004, many mutations responsible for inherited disease in dogs have been identified. This has led to the development of DNA tests for a wide range of inherited traits in dogs, and tests for genetic diseases in other companion species are also becoming available. With increasing emphasis being placed on improving the health of purebred dogs, DNA testing is likely to be an important tool for breeders as they strive to improve the genetic healthof their dogs. Therefore, there is an urgent need for vets to be well informed about genetic testing, as they will undoubtedly be the first port of call for many owners and breeders seeking both general advice as well as information regarding the benefits and limitations of specific DNA tests. This article explains the principles of DNA testing and highlights the tests that are currently available commercially. While the article focuses on DNA testing in dogs, the principles discussed are broadly applicable to any species. In December 2004, a $30m project funded by the National Human Genome Research Institute (NHGRI) in the US to sequence the entire dog genome was completed and the results made publicly available. The NHGRI made the decision to fund such an expensive project because it recognised the dog as an unrivalled model organism with which to study the genetics of inherited disease. Although the NHGRI's motives for sequencing all the DNA in the dog were primarily human-centric, the findings that emerged a little over five years ago have had profound implications for both veterinary and human medical research. Most importantly (for dogs) is that the pace at which genetic mutations responsible for inherited canine diseases have been discoveredhas increased dramatically and will continue to do so, as the tools available to dissect the genetic basis of canine inherited traits become increasingly more sophisticated. Currently DNA tests are available for close to 100 different canine mutations, and over 120 breeds are able to take advantage of at least one DNA test. As pressure to improve the health of purebred dogs continues to intensify dog breeders will come under increasing pressure to make full use of all the DNA tests available to them, and many will turn to their vets for advice and information regarding the benefits as well as the limitations of specific DNA tests.