Selection Makes The Purebred

[shortstep]

How Do You Make the Perfect Sled Dog?

ScienceDaily (Sep. 25, 2010) — Over the last few hundred years, Alaskan sled dogs have been bred to haul cargo over Arctic terrain and, more recently, for racing. Now, researchers writing in the open access journal BMC Genetics have identified the contributions different breeds have made to the speed, endurance and work ethic of Alaskan sled dogs.

Heather Huson and Elaine Ostrander, from the National Institutes of Health, Bethesda, USA, worked with a team of researchers to carry out genetic analysis in 199 sled dogs and 681 purebred dogs from 141 different breeds. Huson said, "The Alaskan sled dog comprises several different lineages, optimized for different racing styles -- long or short distance. We sought to identify breed composition profiles associated with expertise at specific tasks, finding that the Alaskan Malamute and Siberian Husky contributions are associated with enhanced endurance; Pointer and Saluki are associated with enhanced speed and the Anatolian Shepherd has a positive influence on work ethic."

The researchers sampled sled dogs from eight kennels, rating them for speed, endurance, and work ethic, using established criteria specified for the distinct racing styles of sprint and distance. These attributes were correlated with genetic information taken from each dog and compared to likely ancestral breeds.

Speaking about the results, Huson said, "The Alaskan sled dog presents a case in which a genetically distinct breed of dog has been developed through the selection and breeding of individuals based solely on their athletic prowess.

Interestingly, this continual out-crossing for athletic enhancement has still led to the Alaskan sled dog repeatedly producing its own unique genetic signature.

Indeed, the Alaskan sled dog breed proved to be more genetically distinct than breeds of similar heritage such as the Alaskan Malamute and Siberian Husky."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by BioMed Central, via EurekAlert!, a service of AAAS.

Journal Reference:

Heather J Huson, Heidi G Parker, Jonathan Runstadler and Elaine A Ostrander. A genetic dissection of breed composition and performance enhancement in the Alaskan sled dog. BMC Genetics, 2010; (in press) [link]

Gives a whole new look at the concept of purebred doesn't it.

Edited June 1, 2011 by shortstep

[shortstep]

Followed by more purebred genetics

http://www.sciencedaily.com/releases/2007/05/070510090442.htm

Life As A Dog Means Faster Mutations

ScienceDaily (May 10, 2007) — It may be hard to see that the Chinese crested dog is descended from the wolf, but it’s easier to grasp that two poodles of different sizes are related. In her dissertation presented on May 3, Susanne Björnefeldt, at the Department of Evolution, Genomics, and Systematics at Uppsala University, shows that dogs of the same breed differ more genetically than was previously thought.

The wolf is the first animal that humans domesticated. Even though all dogs descend from the wolf, today dogs occur in more variants than any other mammal. These variations are not only the result of breeding, but also of the comfortable life dogs lead, a life that has entailed genetic changes. We might expect dogs to be genetically different from those of another breed, but we might also be led to believe that they are relatively similar within a single breed.

But in fact dogs of the same breed are genetically more different than we thought, according to Susanne Björnefeldt. She mentions the poodle as an example: it is genetically divided into five groups, although kennel clubs divide the poodle into four distinct groups.

In her dissertation Susanne Björnefeldt has primarily compared the mitochondrial DNA of the dog with that of the wolf and found that more protein changes have taken place in dogs over a shorter period than in the case of their wolf ancestors.

Dogs have mutated more rapidly than wolves.

Many of these mutations can be harmful to the animal.

Whereas wolves have eliminated most altered characteristics through natural selection (a wild wolf with inferior characteristics will not be allowed to mate), dogs have been able to pass on their mutations, for better or worse.

“One advantage is that it is easier to use the dog as an experimental animal in scientific studies in order to facilitate the search for pathogenic genes.

A drawback, however, is that thoroughbred dogs are more susceptible to diseases,” says Susanne Björnefeldt, ....

Reference: Consequences of the Domestication of Mans Best Friend, The Dog, ISBN: 978-91-554-6854-5

[idigadog]

How Do You Make the Perfect Sled Dog?

Wish I knew ;)