Balancing Selection on CDH2 May Be Related to the Behavioral Features of the Belgian Malinois

Abstract

The Belgian Malinois (BM) is an excellent working dog that typically shows a circling behavior when placed in a confined space. Moreover, individuals showing moderate running in circles (one kind of obsessive compulsive behavior) in confined spaces typically show better work performance compared to those without the circling behavior or to those with a serious circling behavior (which can be defined as an obsessive compulsive disorder (OCD)). To determine whether the candidate gene CDH2, Cadherin 2, which is associated with OCD in the Doberman pinscher breed of dogs and in humans, was linked with this behavioral character in the BM, population genetic analyses were performed on a BM population and a natural population of the Chinese indigenous dog (CID). Many genetic signals of balancing selection were detected for one specific region of the CDH2 gene, which suggests that a genomic block, which is included in the CDH2 gene, experienced balancing selection in the BM, and that the CDH2 gene might be associated with the behavioral characteristics of the BM dog (a balance between circling behavior and work performance). Moreover one specific variant, G63913941A, which creates a predicted transcription factor-binding site, may be the key mutation in the CDH2 gene affecting the behavior of BMs by allowing the binding of a transcription factor and increasing CDH2 expression.

Phenotypic determination of noise reactivity in 3 breeds of working dogs: A cautionary tale of age, breed, behavioral assessment, and genetics

“…As a result, breeding of dogs and genetic lines that may be at enhanced risk for behavioral pathology continues without the benefit of genetic and behavioral counseling. While dogs with behavioral conditions are excellent natural animal models for human psychiatric illnesses (Overall, 2000;Overall et al, 2001;Overall and Dunham, 2002;Dodman et al, 2010Dodman et al, , 2016Ogata et al, 2013;Cao et al, 2014), breed and individual health is primary and is improved by establishing and participating in such studies (O'Neill et al, 2014;Overall et al, 2014;van Rooy et al, 2014).…”

“…It is also possible that by selecting for some attribute, an extreme variant of some behavioral association was selected for and expression varied depending on the dog's environment (Tiira et al, 2012) or utility, resulting in a series of liability genes contributing to various behavioral expressions. Cao et al (2014) proposed the latter process for Belgian malinois, where circling and tail chasing is frequently seen in working dogs, resulting in balancing selection for a genomic block of the CDH2 gene. It is possible that a similar process has occurred for noise reactivity/phobias in any of these breeds, were one to select for some degree of heightened responsivity.…”

Whole genome analyses reveal significant convergence in obsessive-compulsive disorder between humans and dogs

“…We also examined the previously reported CCD-associated genes, including neuronal cadherin (CDH2) [22,23,60], catenin alpha 2 (CTNNA2) [22], ataxin-1 (ATXN1) [22], and plasma glutamate carboxypeptidase (PGCP) [22] in our sample. We found that SNPs within these genes (22 SNPs in CDH2, 12 SNPs in CTNNA2 and 81 SNPs in PGCP) exhibited significant differences between cases and controls at nominal P value of 0.05 (Chi-square tests), and the probability of observing normal significant SNPs in three of four genes was zero in randomly-selected genes (Supplementary Methods online).…”

Selecting Dogs for Explosives Detection: Behavioral Characteristics

“…However, high energy and activity is often associated with increased arousal. For example, Belgian Malinois bred as MWDs exhibit high levels of excitement often resulting in spinning behavior when kenneled, which has been reported to be higher in individuals with better work performance due to a stronger desire to work (42). Maejima et al (33) found that higher levels of anxiety were associated with a stronger desire for work and successful certification as a drug detection dog.…”