Deep sequencing of Korean Jindo dog reveals evolutionary trajectory of coat color variations.

The inherent diversity of canines is closely intertwined with the unique color patterns of each dog population. These variations in color patterns are believed to have originated through mutations and selective breeding practices that occurred during and after the domestication of dogs from wolves. To address the significant gaps that persist in comprehending the evolutionary processes that underlie the development of these patterns, we generated and analyzed deep-sequenced genomes of 113 Korean Indigenous Jindo dogs that represent five distinct color patterns to identify the associated mutations in CBD103, ASIP, and MC1R. The degree of linkage disequilibrium and estimated allelic ages consistently indicate that the black-and-tan dogs descend from the first major founding population on Jindo island, compatible with the documented literature. We additionally demonstrate that black-and-tan dogs, in contrast to other color variations within the breed, exhibit a closer genetic affinity to ancient wolves from western Eurasia than those from eastern Eurasia. Lastly, the alleles unique to black-and-tan dogs indicated a pleiotropic effect by significantly decreasing the body size phenotypes compared to non-carriers. Overall, comparisons of whole genome sequences of each coat color population diverged from the same breed provided an unprecedented glimpse into the properties of evolutionary processes maintaining variation in Korean Jindo dog populations.