Unravelling selection signatures in a single dog breed suggests recent selection for morphological and behavioral traits

Abstract

Strong selection has resulted in substantial morphological and behavioral diversity across modern dog breeds, which makes dogs interesting model animals to study the underlying genetic architecture of these traits. However, results from between-breed analyses may confound selection signatures for behavior and morphological features that were coselected during breed development. In this study, we assess population genetic differences in a unique resource of dogs of the same breed but with systematic behavioral selection in only one population. We exploit these different breeding backgrounds to identify signatures of recent selection. Selection signatures within populations were found on chromosomes 4 and 19, with the strongest signals in behavior-related genes. Regions showing strong signals of divergent selection were located on chromosomes 1, 24, and 32, and include candidate genes for both physical features and behavior. Some of the selection signatures appear to be driven by loci associated with coat color (Chr 24; ASIP) and length (Chr 32; FGF5), while others showed evidence of association with behavior. Our findings suggest that signatures of selection within dog breeds have been driven by selection for morphology and behavior. Furthermore, we demonstrate that combining selection scans with association analyses is effective for dissecting the traits under selection.

Genetic testing of dogs predicts problem behaviors in clinical and nonclinical samples

“…Control of population structure is critical to genetic studies of domesticated species 4,21,44 . We previously mitigated the effects of population structure by using linear mixed models and multiple cohorts with partially overlapping breed makeup in the discovery GWASs 11,12 .…”

“…Breed popularity is so unbalanced that the 10 most popular breeds accounted for 50% of all 2008 AKC registrations. We cannot rule out the effects of population structure on our studies or that some behavioral variants are part of, or inextricable from, population structure 4,21,44 . However, population structure is not a critical problem here because markers that are correlated genetically are not correlated with the same traits.…”

“…The correlation of body size and behavior in dogs has thus been observed in behavioral [17][18][19][20] and genetic studies 11,12 . Based on biological relevance, we previously argued that behavior-body size correlations are due to pleiotropy 12 (rather than population structure 21 ). We and others have now strengthened that evidence greatly 11,22 .…”

Genetic testing of dogs predicts problem behaviors in clinical and nonclinical samples

“…Control of population structure is critical to genetic studies of domesticated species [ 4 , 21 , 42 ]. We previously mitigated the effects of population structure by using linear mixed models and multiple cohorts with partially overlapping breed makeup in the discovery GWASs [ 11 , 12 ].…”

“…The correlation of body size and behavior in dogs has thus been observed in behavioral [ 17 – 20 ] and genetic studies [ 11 , 12 ]. Based on biological relevance, we previously argued that behavior-body size correlations are due to pleiotropy [ 12 ] (rather than population structure [ 21 ]). We and others have now strengthened that evidence greatly [ 11 , 22 ].…”