Each year the American Kennel Club hosts the AKC/Eukanuba National Championship for owners or purebred dogs to come and compete. Awards such as the Canine Excellence award not only earn you and your dog a fancy shining metal, but the winner also receives a cash of $1000. Not a bad reason to want to own a purebred. It turns out though that purebreds are much more valuable than a family pet or award winning competitor in dog shows. Studying the genetic genomes of purebred dogs can help in the fight against cancer by allowing scientists to better understand which genes are associated with specific cancers as well as other diseases. 
But how could studying an animal which physically is so different from us? Well it turns out that the human and canine genome differs by less than 2%? This similarity has stuck interest in numerous scientists including those focused on stem cell research and those studying cancer. Of the near “400 known hereditary canine diseases, more than half have an equivalent human disease”. These diseases and other conditions such as blindness, deafness, mental disorders, diabetes, and numerous forms of cancers occur naturally in both dogs and humans. These links between humans and canines makes them the perfect species to study the interactions between multiple environmental factors and genes in their role on cancer outside our own species. By sequencing the canine genome and understanding certain disease mechanisms as they play out in dogs could help us compare these diseases in humans and achieve a better understanding of how they come about.
Yet, why specifically are purebreds the one beings studied? Why not study any dog to study its genome? Well, the great thing about purebreds is they act as mini populations which have limitations of what has been added into their gene pool. Different breeds have unique microsatellites which are short repeating DNA sequences which act as markers used to certify dogs as a specific breed. These microsatellites are unique genetic signatures, thus individuals within the same breed have very similar DNA sequences, making it very easy to compare and detect any differences. Within breeds, there are less sequence variations than humans.In terms of sequencing human DNA and finding similarities or differences is that the trail will almost always go cold since there might not be a sufficient number of family members with the disease to truly pin down the source. Studying the canine genome will be far more efficient since on average only about 30,000 single nucleotide polymorphisms would need to be isolated in canines compared to the 400,000 in the human genome. Clearly studying the canine genome could save both a lot of time and money and overall may help understand cancer sooner than simply studying humans. Sequencing the canine genome will help scientists understand their genetic basis for diseases and track the disease across different breeds.
One study was able to find a link between canine hereditary multifocal renal cystadenocarcinoma and nodular dermatofibrosis (RCND) and human renal cancer. RCND and renal cancer have similar symptoms such as firm nodules in the skin and kidney tumors. RCND is naturally inherited by German Shepherds so they mapped the genomes of members of a Norwegian dog family. They were able to link RCND on chromosome 5 (CFA5) in canines. It turns out that humans have corresponding CFA5 portions in HAS 11q, 17p, 1p, and 16q. Mutations in these regions are what cause renal cancer in humans and RCND in dogs. More research will hopefully help scientists of renal cancer in humans and what triggers these mutations in these specific regions.Resources:
1.http://www.sciencemag.org/content/304/5674/1093.1.full?sid=101a6f7b-8b7a-49dc-9ce6-3e5837099287
3.http://hmg.oxfordjournals.org/content/17/R1/R42.full.pdf+html?sid=5bd7b3bd-3ba3-42a8-b4da-57ead06ef5a1
4. http://www.sciencentral.com/articles/view.php3?language=english&type=&article_id=218392128&PHPSESSID=91dd2abe1ba93fc31b446d6499ea00fb
5. http://www.sciencentral.com/articles/view.php3?type=article&article_id=218392296
