| Abstract: | Domestic dogs exhibit tremendous phenotypic diversity, including a greatervariation in body size than any other terrestrial mammal. Here, we generate ahigh density map of canine genetic variation by genotyping 915 dogs from 80domestic dog breeds, 83 wild canids, and 10 outbred African shelter dogs across60,968 single-nucleotide polymorphisms (SNPs). Coupling this genomic resourcewith external measurements from breed standards and individuals as well asskeletal measurements from museum specimens, we identify 51 regions of the doggenome associated with phenotypic variation among breeds in 57 traits. Thecomplex traits include average breed body size and external body dimensions andcranial, dental, and long bone shape and size with and without allometricscaling. In contrast to the results from association mapping of quantitativetraits in humans and domesticated plants, we find that across dog breeds, asmall number of quantitative trait loci (≤3) explain the majority ofphenotypic variation for most of the traits we studied. In addition, manygenomic regions show signatures of recent selection, with most of the highlydifferentiated regions being associated with breed-defining traits such as bodysize, coat characteristics, and ear floppiness. Our results demonstrate theefficacy of mapping multiple traits in the domestic dog using a database ofgenotyped individuals and highlight the important role human-directed selectionhas played in altering the genetic architecture of key traits in this importantspecies. |
