Genetic Underpinnings of Canine Obesity

PhD project strategic theme: Biosciences for an integrated understanding of health

My research will focus on the genetics of obesity in dogs. We will use a combination of bioinformatic, cellular, and whole-dog models to examine gene association with obesogenic traits both within breeds and across breeds. Therefore providing insight for both treatment and prevention of this disease. We study dogs to provide insight into novel genes and mechanisms of obesity in multiple species. The dog is a compelling model organism for the study of obesity because pet dogs have increasing levels of obesity, influenced by many of the same environmental factors as humans, but a very different genetic architecture which makes trait mapping uniquely tractable in the species. Extensive artificial selection has resulted in over 200 distinct breeds of dog with huge diversity between them. Very small founder populations and population bottlenecks has resulted in long range linkage disequilibrium aligned to high homozygosity within breeds, which means complex traits can be mapped with fewer individuals and fewer markers than in human populations (although to much larger loci). Cryptic relatedness and population stratification mean that application of statistical models relevant to family-based studies in humans are essential even for studies within one dog breed, most notably linear mixed models. Furthermore, the recent advent of a higher density canine SNP array means that studies in crossbred (mongrel) dogs is theoretically possible. We also plan to undertake comparative analysis for both humans and other mammalian species. Therefore, studying dogs as a model for complex disease provides potential for insight into novel genes and mechanisms of obesity and we plan to elucidate some of the genetic architecture behind obesity predisposition.