Candidate genes for social behavior, cortisol level, and the personality of common marmosets, Callithrix jacchus

抄録

Specific genotypes of arginine vasopressin receptor 1a (AVPR1a) and μ-opioid receptor (OPRM1) genes are related to social behavior in humans, chimpanzees, and rhesus monkeys. We surveyed these candidate genes in 77 captive common marmosets and found (GT)n polymorphism located in the intron of AVPR1a where 10 alleles were categorized as either being short (S: 202-210bp) or long (L: 212-222bp). We also found A111T (Leu37Phe) and T329C SNPs in OPRM1. Personality was assessed by ratings by three individuals familiar with each marmoset on the Hominoid Personality Questionnaire. Principal components analysis on 47 personality items yielded three domains labeled Dominance, Sociability, and Neuroticism. We conducted preliminary tests with unadjusted linear models to determine whether these personality domains were associated with AVPR1a or OPRM1 polymorphisms. For Sociability, marmosets possessing the SS genotype of AVPR1a were significantly higher than marmosets possessing the LL genotype. For Neuroticism, marmosets possessing the SL or SS AVPR1a genotype were significantly lower than marmosets possessing the LL genotype. Also in OPRM1 polymorphisms marmosets with the T/T genotype of both loci were higher and lower in Neuroticism, respectively. Finally we obtained cortisol hormone levels from hair samples and tested whether cortisol levels were related to genotype and/or personality. These findings, although preliminary, suggest that the same genes are responsible for personality variation across all three taxonomic families of primates.