Genomic evidence for behavioral adaptation of herding dogs

Herding dogs exhibit a distinct constellation of behaviors marked by inherent instinct and motor skills that manipulate and guide livestock in response to instructive commands and cues. Comparison of the whole-genome sequences of herding and nonherding breeds reveals signatures of positive selection associated with pathways underlying social interaction and cognitive functions. Of the strong selective sweep signals, haplotypes within ephrin type-B receptor 1 (EPHB1), which is linked to locomotor hyperactivity and spatial memory, show evidence of segregation within breed lineages for the conformation versus working lines of border collies and introgression with a genetically and geographically distant herding breed of Entlebucher mountain dogs. We show that a working line-specific haplotype of EPHB1 is associated with elevated levels of chase-bite motor patterns based on a well-validated behavior survey. These findings indicate that functional selection has shaped the genetic architecture of herding breeds, which may relate to their proficiency in addressing diverse tasks and challenges in maintaining control over the herd.