A genetic variation in the arginine vasopressin V1a receptor gene (AVPR1A) was recently linked to receptive joint attention deficiency by researches at Yerkes National Primate Research Center, Emory University, together with a team of researchers from other institutions, including University of Texas M.D. Anderson Cancer Center. These findings are significant because individuals lacking in joint attention have also been associated with developmental disorders, including autism spectrum disorder (ASD) as well as certain language impairments. Moreover, associations between receptive joint attention performance and social rank/dominance were also found mediated by variations in the chimpanzee’s AVPR1A gene, providing further supportive data for specific social evolutionary hypotheses. The results were published on January 20th 2014 in Scientific Reports.
Yerkes researchers Larry Young, PhD, and Bill Hopkins, PhD, both co-authors of the study, showed that chimpanzees were polymorphic for a deletion in the 5′ flanking region of the AVPR1A gene sequence, referred to as DupB. Socio-communicative cues and performance was enhanced in males with one DupB+ allele compared to males homozygous for the DupB- deletion. Moreover, the chimpanzee’s social cognition performance was found to be heritable. However, female chimpanzees were not affected by this gene disruption. This is consistent with previous human studies in which AVPR1A influenced male social behaviors and not female. In these studies, the AVPR1A gene disruption was specific for social cognition because no influence on the performance of a non-social cognition task was detected. Critical to the development of these studies and the acceptance of the current results, the authors previously showed that AVPR1A was required for social memories and bonding in male rodents.
The AVPR1A genetic region has been associated with variation in social behavior in humans as well as linked to the development of ASD. According to the authors of this research chimpanzees represent an excellent model to study the functional role of the AVPR1A gene because of the high level of desired genetic manipulation in the AVPR1A region. The overall similarities between chimpanzees and humans also make chimpanzees an attractive model. These studies suggest an exciting potential role for AVPR1A as a genetic marker in order to better understand autism and other cognitive defects in humans.