Canine morphology: Hunting for genes and tracking mutations

Abstract

As a result of domestication, selection for desirable phenotypes, and breed propagation, the domestic dog is unmatched in its diversity as a land mammal. Exhibiting extraordinary levels of both interbreed heterogeneity and intrabreed homogeneity, evidenced in part by the extensive linkage disequilibrium observed in many breeds, the dog provides an as-yet unrealized opportunity to uncover the molecular mechanisms that govern natural variation across mammalian species. We herein discuss recent advances in canine genomics that have made exploration of genetic mechanisms controlling breedspecific differences possible. We consider some examples where molecular mechanisms controlling simple traits have been uncovered. Finally, we reveal how combinations of genes produce complex phenotypes that can be revealed through studies of dog breeds featuring specific traits.