Alaskan sled dogs do not belong to one pure breed, but rather are a blend of several different purebred breeds that were combined to optimize for strength, speed, and trainability. Using genetic ancestry analysis, the team of researchers were able to confirm that sprinter and long distance racer dogs have significant differences in their breed blends. Using purebred Alaskan malamute, Siberian huskies, German shorthaired pointers, and borzois for reference, they established that sprinter dogs have a considerably larger dose of German shorthaired pointer ancestry and long-distance race dogs have more Alaskan malamute and Siberian husky ancestry. The authors suggest that dogs with more husky ancestry have more “mental toughness,” a necessity for the long hauls, whereas dogs with more pointer ancestry may be easier to train and are more eager to please and perform.
The researchers also did a genome-wide association study looking for genetic factors that influence heat tolerance in both sprinters and in long-distance racers. They found that seven SNPs within one gene — MYH9 — were associated with the ability to perform well even in the heat. The dog days of summer perhaps don’t feel so hot for these lucky pooches. There is a similar version of this gene in humans, but more research is needed to determine whether variation in this gene affects human heat tolerance.As we watch the Olympics in London this summer, we won’t see any four-legged friends on the winner’s podium. Nevertheless, Alaskan sled dogs are tremendous athletes, and genetic studies such as this one may offer insights into the amazing athletic talents of those who actually will be on the podium.