Genetic dissection of behavioral traits related to successful training in drug-detection dogs

Drug detection dogs play integral roles in society; however, the interplay between their behaviors and genetic characteristics remains uninvestigated. To profile the genetic traits associated with various behaviors related to the successful training of drug detection dogs, we collected and analyzed more than 230,000 genetic variants from 326 dogs belonging to the German Shepherd or Labrador Retriever breeds. Behavioral breed differences were observed in ‘friendliness to humans’ and ‘tolerance to dogs’. A strong positive correlation was observed in the genomic heritability of behavioral traits between breeds (Pearson’s r  = 0.964, P  = 0.008), indicating a similar degree of genetic influence on the behavioral traits between breeds. A genome-wide association study identified 18 single nucleotide polymorphisms potentially associated with drug detection abilities and three behavioral traits (interest in the dummy, tolerance to dogs, and friendliness to humans) related to drug detection abilities. Among them, 61 protein coding genes, including those associated with anxiety-related or exploration behavior in mice, such as Atat1 and Pfn2 , were located surrounding the candidate polymorphisms. These findings highlight genetic characteristics associated with behavioral traits that are important for the successful training of drug detection dogs, which might support improved breeding and training of these dogs.