Date of Award

Summer 7-18-2016

Degree Type


Degree Name

Master of Science in Integrative Biology (MSIB)



Major Professor

Jared Taglialatela

First Committee Member

Martin Hudson

Second Committee Member

Joel McNeil


Among the great apes, chimpanzees are unique in having a polymorphic deletion of a ~350bp microsatellite containing region (DupB) in the 5’ flanking region of the arginine vasopressin receptor 1a (AVPR1a) gene. This results in three genotypes (DupB+/+, DupB+/- and DupB-/-) of AVPR1a in chimpanzees. Variations in the length of microsatellites 5’ of AVPR1a have been associated with social behaviors (pair-bonding, paternal care, degree of social interest) and differential levels of expression of AVPR1a in the brains of voles. The polymorphic DupB microsatellite in chimpanzees allows the investigation of microsatellite variation 5’ of AVPR1a in higher order primates. We hypothesized that chimpanzees lacking the DupB microsatellite would spend more time alone (in the absence of conspecific social partners) compared to chimpanzees that retain the ancestral genotype. Additionally we collected identical behavioral data on bonobos, who are not polymorphic for the deletion of this microsatellite in order to make comparisons within the Pan genus on sociality and the impact of a polymorphic deletion of the DupB microsatellite. Finally we conduced luciferase reporter assays in order to investigate the impact of the DupB microsatellite on gene expression. These data indicate that bonobos spend more time close to conspecifics and spend more time grooming, compared to chimpanzees. With respect to the DupB deletion and sociality, these data indicate that chimpanzees with a complete deletion of DupB are more likely to spend time “alone” than DupB+ individuals or bonobos.