Genomic Variation Among Dog Breeds

Canine Morphology: Hunting for Genes and Tracking Mutations is a Science Daily article which notes a paper published in PLOS Biology titled Canine Morphology: Hunting for Genes and Tracking Mutations. This from Science Daily:

ScienceDaily (2010-03-01) -- Why do domestic dogs vary so much in size, shape, coat texture, color and patterning? Study of the dog genome has reached a point where the molecular mechanisms governing such variation across mammalian species are becoming understood.

Dogs are wonderfully amazing in that one species includes over 300 breeds of dogs. Of course the other amazing fact is the variation in different biological properties observed among the many breeds. Canine Morphology: Hunting for Genes and Tracking Mutations was authored by Abigail L. Shearin and Elaine A. Ostrander and appears in the March 2010 edition of PLOS Biology. The summary states:

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 breed-specific 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.

One of the genomic highlights is the observation that combinations of alleles involving only three genes accounts for about 95% of variations in the coats of the 108 AKC breeds studied.