Abstract:
Alaskan sled dogs present us with the unique opportunity to study the development of a population of dogs produced from the selective breeding of high performance athletes. I establish that sled dogs are a genetically distinct population of dogs that segregate into two sub-groups based on their racing style of "sprint" or short distance and "distance" or long distance. The practice of interbreeding Alaskan sled dogs with various purebred dogs over the past century has allowed us to investigate the impact of these domestic breeds on the sled dog genome and their potential contribution to athletic performance. Here, I establish genetic profiles of both the sprint and the distance racing dogs using microsatellite-based markers, single-nucleotide polymorphism (SNP) arrays, and ancestry modeling. Population structure is assessed using clustering and principle component analyses. Inbreeding patterns are examined through population structure, inbreeding statistics, estimations of linkage disequilibrium, and autozygosity. Purebred breed components and their potential role in influencing performance attributes of Alaskan sled dogs were determined through genetic breed identification. Ancestry modeling was used to localize genomic regions of specific breed selection. These breeds were then analyzed for their genetic contribution to regions experiencing selection within the sprint or distance racing dogs. I determined regions of selective sweep and genome-wide association to the sprint or distance racing dogs. A genome-wide association analysis of heat tolerance performance in sprint dogs identified SNPs potentially regulating the MYH9 gene. This was the first genetic assessment of ancestry, inbreeding, and performance genes attributed to racing Alaskan sled dogs.
