News on the Genetics of Canine Behavior
Coming in tomorrow’s issue of Genetics Magazine in an interesting follow up to the historic studies on canine behavioral genetics summarized in a well-known book by Scott and Fuller, a study conducted by staff at the Waltham Center for Pet Nutrition, the University of Utah, Sundowner’s Kennels, and the National Human Genome Research Institute on how genes control size, lifespan, and even complex breed behaviors like pointing and herding.
The entire dog genome was first sequenced in 2005. Since then, canine genetic studies have focused primarily on genes controlling basic traits like coat color and inherited diseases. These studies have necessarily focused for the most part on just a single breed at a time. To study the genetic basis of behavior, a scoring system was developed to rate 148 breeds for traits like herding, pointing, boldness, excitability and trainability.
Dog breeds have largely developed through stringent selection to conform to specific stereotypic criteria of appearance and behavior and the results of the study strongly indicate that most breed-related (phenotypic) standardized (stereotypic) behaviors observed in dogs are the result polygenic factors.
DNA samples isolated from 148 dog breeds were used to associate SNP (single nucleotide polymorphism) markers with breed stereotypes. Size was initially used as a trait to test the method and it allowed the team to identify six significant quantitative trait loci (QTL) on five chromosomes that appear to control the size of dog breeds.
Greg Barsh of Stanford University in California, US, says the research certainly pushes forward the genetic analysis of dog personalities, but he cautions that behaviours may be difficult to explain genetically.
“We’ve learned from human genetics that classifying behaviour is not so easy,” he says. Just as one person’s schizophrenia differs from another’s, collies might herd differently than sheepdogs.
I find it a bit ironic that Dr. Barsh chose to use a comparison of the working styles of ’collies’ and ‘sheepdogs’ (and frankly, I’m not sure at all what he’s referring to with either term) to illustrate the point that the genetic classification of behavior is, at best, in its infancy – IMO it’s a bit like saying that apples aren’t pears. Still, the complex nature of the genetics of behavior is not surprising and it does much to emphasize the importance of considering temperament and performance in breeding every litter of dogs.