Genome-wide association studies to identify loci and variants associated with behavioral traits in dogs – Presented by V.D. Marinescu, PhD

The many dog breeds available today are the result of a careful selection for desired characteristics including behavior, making the domestic dog (Canis familiaris) a promising genomic model for identifying the genes and variants underlying behavioral traits. In Sweden, one of the standardized tests used to evaluate canine behavior is the Dog Mentality Assessment (DMA) that quantifies several aggregated personality traits (aggressiveness, chase proneness, curiosity/fearlessness, playfulness and sociability) based on a number of subtests scoring 33 behavioral variables. The DMA was originally developed to assist in the breeding of working dogs, but since its introduction in 1989, has become widely used for privately owned dogs from working and non-working breeds alike. As a result, it is possible to perform genome-wide association studies (GWAS) for a large number of dogs from different breeds for which DMA results are known and blood samples have already been obtained. In a GWAS mapping behavioral traits across a well-defined population of 442 Swedish German Shepherds, we found loci that were genome-wide significantly associated with playfulness and with individual behavioral variables. These point towards genes involved in synaptic plasticity, axonal navigation and nervous system development. We are currently extending this study to identify associations with behavioral traits in additional breeds displaying large behavioral variability such as Rottweilers, Rough Collies, Flat-Coated Retrievers and Boxers. By understanding the genetic variation associated with a particular trait in a given breed, we hope to facilitate marker assisted selection and to gain further insights into the molecular mechanisms underlying canine behavior.