NIH Distinguished Investigator National Institutes of Health Bethesda, Maryland
The domestic dog has undergone intensive human-driven selective pressure to produce canines of a particular appearance or with a desired behavior pattern. The result has been the development of over 350 modern breeds, all of which are members of the same species, with human-induced or geographic barriers to gene flow, and fixed traits that reliably reproduce through multiple generations. Recent studies in our lab have focused on decoding the genetic basis of morphologic traits that both vary between and define dog breeds, e.g. body size, leg length, coat color, skull shape, etc. This work demonstrates a now recurring theme in dog genetics; many highly variable phenotypes are controlled by variation in small numbers of genes, as opposed to humans, where subtle differences in phenotype tend to be controlled by large numbers of genes, many of which contribute to human disease states. As we show, this difference likely represents the very recent development of most breeds, within the last 300 years. This fact can be exploited to study the genetics of disease risk and identify genomic features underlying both human and canine health.