In the realm of canine studies, research into behavior—particularly non-pathological behaviors—proves intriguing for both dog owners and scientists alike (Serpell, 1995). These behaviors span a wide range from herding and pointing to more abstract qualities like temperament and trainability (Svartberg, 2006). A deeper understanding of the genetics behind these behaviors not only expands our knowledge about dogs but could also shed light on behavioral genetics in other animals, including humans (Overall, 2000).
Dog behaviors are complex traits, determined by a combination of potentially hundreds or even thousands of genes, coupled with environmental factors (vonHoldt et al., 2010). While the specific genes and mechanisms involved are not yet fully understood, studies have highlighted certain behaviors as largely influenced by genetics (Jones et al., 2008). Breed-specific behaviors such as herding in English Shepherds, fetching in Retrievers, and scent tracking in Hounds are thought to be primarily genetically determined. These traits were selected over generations of breeding to meet specific needs (Farrell et al., 2015). However, the genetic influence extends beyond these tasks and impacts a dog’s temperament, physical abilities, and even its trainability and intelligence (Hare et al., 2002).
A pivotal study by Jones et al., (2008) offers significant insights into the genetics of these behaviors. The research analyzed the genetic makeup of 2801 dogs across 147 breeds, using breed averages for specific behaviors and traits. They identified quantitative trait loci (QTLs) significantly associated with behaviors such as pointing, herding, boldness, trainability, and excitability. QTLs are regions of DNA associated with variation in a specific phenotype (observable trait), suggesting that these behaviors are not solely the result of environmental factors but are at least partially influenced by genetics. However, it’s important to emphasize that the identification of QTLs related to behaviors does not imply that these behaviors are entirely determined by genetics. Behaviors are complex traits, and while genetics set the stage, environmental factors and training play significant roles in shaping an individual dog’s behaviors (Scott and Fuller, 1965).
Looking ahead, the identification of intermediate phenotypes or endophenotypes could bring significant advancements (Gottesman and Gould, 2003). Endophenotypes are heritable traits or characteristics that act as an intermediary link between a gene and a complex phenotype. They often manifest as measurable biological markers seen in individuals with a particular genetic predisposition, even before the full-blown phenotype manifests (Gould and Gottesman, 2006). In the context of dog behavior, endophenotypes might manifest as variations in brain structure or activity patterns, hormone levels, or subtler behavioral indicators. As endophenotypes for behaviors are identified and understood, researchers may be able to better pinpoint the genes and genetic variants influencing different behaviors. This type of research may enable more targeted breeding programs if desired, and also could guide potential interventions, such as tailored training strategies or even medications, to manage or modify behaviors (Houpt, 2007).
The exploration of the genetic basis for non-pathological behaviors in dogs is an exciting field of study. As our understanding improves, it may well revolutionize the ways we train, breed, and care for our dogs.
References:
- Farrell, L. L., Schoenebeck, J. J., Wiener, P., Clements, D. N., & Summers, K. M. (2015). The challenges of pedigree dog health: approaches to combating inherited disease. Canine Genetics and Epidemiology, 2(1), 3.
- Gottesman, I. I., & Gould, T. D. (2003). The endophenotype concept in psychiatry: etymology and strategic intentions. American Journal of Psychiatry, 160(4), 636-645.
- Gould, T. D., & Gottesman, II. (2006). Psychiatric endophenotypes and the development of valid animal models. Genes, Brain and Behavior, 5(2), 113-119.
- Hare, B., Brown, M., Williamson, C., & Tomasello, M. (2002). The domestication of social cognition in dogs. Science, 298(5598), 1634-1636.
- Houpt, K. A. (2007). Genetics of canine behavior. Acta Veterinaria Brno, 76, S11-S16.
- Jones, P., Chase, K., Martin, A., Davern, P., Ostrander, E. A., & Lark, K. G. (2008). Single-nucleotide-polymorphism-based association mapping of dog stereotypes. Genetics, 179(2), 1033-1044.
- Overall, K. L. (2000). Natural animal models of human psychiatric conditions: assessment of mechanism and validity. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 24(5), 727-776.
- Scott, J. P., & Fuller, J. L. (1965). Genetics and the Social Behavior of the Dog. The University of Chicago Press.
- Serpell, J. A. (1995). The domestic dog: its evolution, behavior, and interactions with people. Cambridge University Press.
- Svartberg, K. (2006). Breed-typical behaviour in dogs—Historical remnants or recent constructs?. Applied Animal Behaviour Science, 96(3-4), 293-313.
- vonHoldt, B. M., Pollinger, J. P., Lohmueller, K. E., Han, E., Parker, H. G., Quignon, P., … & Wayne, R. K. (2010). Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication. Nature, 464(7290), 898-902.
