Dopamine D4 receptor genotype variation in free-ranging rhesus macaques and its association with juvenile behavior

Abstract

A polymorphism in the dopamine receptor D4 (DRD4) gene has been associated with significant variation in behavioral impulsivity, novelty-seeking, and risk-taking in humans and other animals. Rhesus macaques are an excellent animal model for research on the genetic basis of behavior using the candidate gene approach. Little is known, however, about allelic variation in DRD4 in large free-ranging populations of rhesus macaques and how this allelic variation relates to emotion regulation and behavior. In this study, we genotyped for the DRD4 polymorphism 178 individuals of different age and sex categories in the free-ranging rhesus macaque population on the island of Cayo Santiago, PR. Moreover, we examined the possible association between DRD4 allelic variation and three measures of juvenile behavior (time spent in proximity to the mother, avoidance of other individuals, and behavioral restlessness). Five different DRD4 alleles (5R, 5.5R, 6R, 6.5R, and 7R) were identified in the subject population. The most common allele was the 5R allele (78.5%), followed by the 7R allele (16.1%). Juveniles carrying the long form of the DRD4 allele (7R) spent less time in proximity to their mothers, avoided other individuals more often, and scored higher on behavioral restlessness than juveniles carrying the shorter alleles. Behavioral restlessness was also influenced by maternal DRD4 genotype. These results highlight both similarities and differences in the relative occurrence of DRD4 alleles and their association with behavior in this rhesus macaque population, other nonhuman primate species or populations, and humans.

Social Decision-Making and the Brain: A Comparative Perspective

“…Since social network position itself cannot be heritable, these findings imply that aspects of social temperament and social skill useful in building connections with others have a genetic basis, which holds the potential of clear translational value for understanding the biological bases of human disorders attended by social impairments. This study and others [119] endorse the potential power of exploiting naturally-occurring variation in genomics and social behavior to understand and develop new treatments for human social pathology. While using this approach, however, researchers will have to be careful about potential epigenetic effects on the expression of those genes, including the oxytocin receptorgene, and their associated sociobehavioral phenotype [120].…”

Adaptive developmental plasticity in rhesus macaques: the serotonin transporter gene interacts with maternal care to affect juvenile social behaviour

“…Each subject was observed for one 30 min period per week using continuous focal sampling methods [69]. The final juvenile behavioural dataset consisted of 497 h of observational data [74]. For the present study, counts of social play were extracted as was the total time observed which ranged from 9 to 11.5 h per subject.…”

No Association between Personality and Candidate Gene Polymorphisms in a Wild Bird Population

“…DRD4 SNP449 in two wild populations of invasive yellow-crowned bishops ( Euplectes afer ) was also found to be positively correlated with neophobic behaviour [ 20 ]. More recently, in free-ranging Rhesus macaques ( Macaca mulatta ) DRD4 polymorphisms have also been associated with bold behaviour [ 21 ]. Conflicting results have been found in association studies investigating SERT in wild populations.…”