title: Oxytocin and vasopressin receptor gene variation as a proximate base for inter- and intraspecific behavioral differences in bonobos and chimpanzees.
abstract: Recent literature has revealed the importance of variation in neuropeptide receptor gene sequences in the regulation of behavioral phenotypic variation. Here we focus on polymorphisms in the oxytocin receptor gene (OXTR) and vasopressin receptor gene 1a (Avpr1a) in chimpanzees and bonobos. In humans, a single nucleotide polymorphism (SNP) in the third intron of OXTR (rs53576 SNP (A/G)) is linked with social behavior, with the risk allele (A) carriers showing reduced levels of empathy and prosociality. Bonobos and chimpanzees differ in these same traits, therefore we hypothesized that these differences might be reflected in variation at the rs53576 position. We sequenced a 320 bp region surrounding rs53576 but found no indications of this SNP in the genus Pan. However, we identified previously unreported SNP variation in the chimpanzee OXTR sequence that differs from both humans and bonobos. Humans and bonobos have previously been shown to have a more similar 5' promoter region of Avpr1a when compared to chimpanzees, who are polymorphic for the deletion of ∼ 360 bp in this region (+/- DupB) which includes a microsatellite (RS3). RS3 has been linked with variation in levels of social bonding, potentially explaining part of the interspecies behavioral differences found in bonobos, chimpanzees and humans. To date, results for bonobos have been based on small sample sizes. Our results confirmed that there is no DupB deletion in bonobos with a sample size comprising approximately 90% of the captive founder population, whereas in chimpanzees the deletion of DupB had the highest frequency. Because of the higher frequency of DupB alleles in our bonobo population, we suggest that the presence of this microsatellite may partly reflect documented differences in levels of sociability found in bonobos and chimpanzees.
authors.affiliation: University of Antwerp, Department of Biology, Ethology research group, 2610, Antwerp, Belgium; Centre for Research and Conservation, Royal Zoological Society of Antwerp, 2018, Antwerp, Belgium.
authors.forename: Nicky
authors.initials: N
authors.lastname: Staes
authors.affiliation: Centre for Research and Conservation, Royal Zoological Society of Antwerp, 2018, Antwerp, Belgium; University of Antwerp, Department of Biology, Ethology research group, 2610, Antwerp, Belgium.
authors.forename: Jeroen M G
authors.initials: JM
authors.lastname: Stevens
authors.affiliation: Centre for Research and Conservation, Royal Zoological Society of Antwerp, 2018, Antwerp, Belgium; University of Antwerp, Department of Biology, Ethology research group, 2610, Antwerp, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Helsen
authors.affiliation: Centre for Research and Conservation, Royal Zoological Society of Antwerp, 2018, Antwerp, Belgium; Molecular Systematics Unit, Western Australian Museum, Perth, WA 6106, Australia.
authors.forename: Mia
authors.initials: M
authors.lastname: Hillyer
authors.affiliation: San Diego Zoo Institute for Conservation Research, Escondido, CA 92027, United States of America.
authors.forename: Marisa
authors.initials: M
authors.lastname: Korody
authors.affiliation: University of Antwerp, Department of Biology, Ethology research group, 2610, Antwerp, Belgium.
authors.forename: Marcel
authors.initials: M
authors.lastname: Eens
mesh_terms: D000483:Alleles; D000818:Animals; D001483:Base Sequence; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008969:Molecular Sequence Data; D019974:Pan paniscus; D002679:Pan troglodytes; D020641:Polymorphism, Single Nucleotide; D018045:Receptors, Oxytocin / Q000235:genetics*; D017483:Receptors, Vasopressin / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D012919:Social Behavior
chemical_list: D018045:Receptors, Oxytocin; D017483:Receptors, Vasopressin