Abstract # 4531 Poster # 77:

Scheduled for Thursday, June 20, 2013 07:00 PM-09:00 PM: Session 9 (SG Foyer ABC) Poster Presentation


DOPAMINE D4 RECEPTOR GENE (DRD4) VARIATION PREDICTS INCREASED AGGRESSION IN RHESUS MACAQUES

J. G. Clemente1, S. G. Lindell1, J. D. Higley2, S. J. Soumi3 and C. S. Barr1
1NIH/NIAAA/LNG/SCBG, 5625 Fishers Lane, Room 3S32, Rockville, MD 20852, USA, 2BYU/Psychology, 3NIH/NICHD/LCE
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     Dopamine neurotransmission underlies many reinforcing processes. In humans, a 7-repeat allele (7R) for the DRD4 gene reduces efficacy of the receptor and is linked with traits such as sensation seeking and aggression. Macaque species exhibit orthologous variation at DRD4, with the 4R and 5R alleles having been reported at varying frequencies across species. We wanted to determine whether the functional 7R allele was present in rhesus macaques and whether DRD4 genotype predicted individual differences in behavior. A portion of exon 3 was amplified using PCR, and alleles were called by performing gel electrophoresis and SYBR Safe staining. Rhesus macaques (Macaca mulatta, N= 106) were tested using an Intruder Challenge Test, in which sex- and age-matched, unfamiliar conspecific was presented and behavioral responses recorded. Effects of allelic variation on behavior were then performed using ANOVA. We identified 4R, 5R, 6R, and 7R alleles in our colony. Compared to the ancestral allele (4R), the loss-of-function 7R allele (allele frequency = 9%) predicted increased aggressive responses to social intrusion (p < 0.05). The DRD4 7R allele has been shown to be under positive selection in humans, presumably through its affects on behavior. Our data show that the 7R allele is present in macaques and that it moderates behavioral responses to threat in a manner that could confer selective advantage in certain environmental contexts.