Abstract # 69:

Scheduled for Thursday, August 18, 2005 07:00 PM-09:00 PM: (Cambridge/Oxford Room) Poster Presentation

Functional variation of the Macaca mulatta CRH gene is associated with temperament and reproductive outcome

R. L. Dvoskin1,2,3, C. S. Barr3, S. B. Higley3, C. Shannon3, S. G. Lindell3, D. Goldman3 and J. D. Higley3
1New York University, Department of Anthropology, New York, NY 10003, USA, 2New York Consortium in Evolutionary Primatology, 3NIAAA, NIH
     Corticotropin-releasing hormone (CRH) regulates behavioral, neuroendocrine, and reproductive responses to stress. Variation in CRH activity may underlie individual and species differences in physiological reactivity and behavior. CRH is uniquely expressed in primate placenta and affects timing of birth. Given the tight link between stress and reproduction in primates, we hypothesized that functional variation in the Macaca mulatta CRH gene would relate to temperament and reproductive outcome. We identified 13 variable loci in the CRH gene and promoter that occur in allelic identity in our rhesus colony (15% heterozygotes) and include a polymorphism located within a putative binding site important for CRH expression. Individuals with the rarer haplotype, which was shown by reporter assay to yield higher CRH expression, had higher cortisol levels during temporary separation from their mothers (ANOVA; n = 55, P < 0.05). We found an interactive effect of sex and genotype on birth weight, such that females with the less common haplotype were relatively small (n = 91, P < 0.05). Preliminary analyses indicated that mothers with the more “reactive” genotype spent more time in ventral contact with their infants, although these results were not statistically significant with the current sample size (ANOVA: F1, 67 = 2.97; P = 0.09). While one genotype may be associated with seemingly disadvantageous traits like low birth weight, it could also relate to adaptive social behavior. Studying CRH gene variation may help us understand the co-evolution of stress physiology, behavior, and life history in primates.