Association between COMT SNP variation and timidity in Golden and Labrador Retrievers

Area of Science:

• Canine genetics and behavior
• Molecular biology and animal science

Background:

• Timidity in dogs is highly heritable, but its genetic underpinnings remain largely unknown.
• The catechol-O-methyl transferase (COMT) gene is implicated in human anxiety, with its p.Val158Met polymorphism linked to anxious behaviors.

Purpose of the Study:

• To investigate the correlation between specific single nucleotide polymorphism (SNP) variations in the canine COMT gene and timidity.
• To identify genetic markers associated with temperament in Labrador Retrievers (LR) and Golden Retrievers (GR).

Main Methods:

• Dog courage assessment assay and genotype/haplotype analysis were performed on LR and GR.
• Four COMT gene SNP variations (C.-1666C>G, c.39A>G, c.216G>A, c.482G>A) were analyzed.
• Statistical analyses, including Hardy-Weinberg equilibrium and principal components analysis, were conducted.

Main Results:

• COMT gene genotypes and haplotypes were significantly correlated with dog timidity.
• The c.39A>G locus was excluded due to significant between-breed genotype distribution differences.
• Alleles A at COMT:c.216G>A and c.482G>A were dominant factors in timid behavior.

Conclusions:

• The study identifies specific COMT gene variations as predictive genetic markers for canine timidity.
• Findings support and expand the warrior/worrier hypothesis, offering insights into dog temperament evolution.
• This research has implications for understanding and potentially managing fear and anxiety in dogs.