Related Experiment Video
Updated: Jan 3, 2026
Analysis of Simian Immunodeficiency Virus-specific CD8+ T-cells in Rhesus Macaques by Peptide-MHC-I Tetramer Staining
Published on: December 23, 2016
Monoamine oxidase polymorphisms in rhesus and Japanese macaques (Macaca mulatta and M. fuscata)
Danielle N Jones1, Cody A Ruiz2, Mary Ann Raghanti1
1Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, OH, USA; Brain Health Research Institute, Kent State University, Kent, OH, USA.
Abstract:
Monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B) are enzymes that degrade several monoamines of the central nervous system and have long been implicated in the modulation of social behavior. Macaque monkeys are a suitable model for investigating the role of functional monoamine oxidase polymorphisms in behavior modulation given the high amount of social diversity among the nearly two dozen species. The present study reports allele frequencies for two polymorphisms, MAOA-LPR and MBin2, in samples of rhesus (Macaca mulatta) and Japanese (M. fuscata) macaques. Our results suggest that the two species may differ in high- and low-activity MAOA-LPR allele frequencies. Specifically, 89% of the Japanese macaque alleles in our sample were the low-activity variant, whereas only 41% of the rhesus macaque alleles were of this sort. In our samples, the two species possessed similar allelic variation at the MBin2 locus, with each possessing some species-specific alleles. We also tested for associations between MAOA-LPR genotype and plasma serotonin (5-HT) and dopamine (DA) concentrations in a subset of rhesus macaques, which revealed no association with genotype. Our findings point toward potential differences in the monoaminergic system of two closely related macaque species. Discussion of our results are centered on implications for future investigations that aim to better understand the functionality of monoamine oxidase polymorphisms in the context of primate social behavior.
Insights
Japanese macaques show higher frequencies of low-activity Monoamine Oxidase A (MAO-A) variants compared to rhesus macaques. These MAO-A gene differences may influence primate social behavior and monoamine levels.
Area of Science:
- Neuroscience
- Primatology
- Behavioral Genetics
Background:
- Monoamine oxidase A (MAO-A) and B (MAO-B) enzymes regulate neurotransmitters crucial for social behavior.
- Macaque monkeys offer diverse species for studying gene-behavior links.
Purpose of the Study:
- To determine allele frequencies of MAOA-LPR and MBin2 polymorphisms in rhesus and Japanese macaques.
- To explore potential differences in monoamine oxidase gene variants between these species.
Main Methods:
- Genotyping for MAOA-LPR and MBin2 polymorphisms in macaque samples.
- Analysis of allele frequencies and comparison between species.
- Testing for associations between MAOA-LPR genotype and plasma serotonin/dopamine.
Main Results:
- Japanese macaques exhibit a higher prevalence of low-activity MAOA-LPR alleles (89%) than rhesus macaques (41%).
- Both species show similar allelic variation at the MBin2 locus, with some unique alleles per species.
- No significant association was found between MAOA-LPR genotype and plasma serotonin or dopamine levels in rhesus macaques.
Conclusions:
- Significant differences in MAOA-LPR allele frequencies exist between Japanese and rhesus macaques.
- These genetic variations may contribute to differences in the monoaminergic systems of these primate species.
- Further research is needed to understand the functional impact of monoamine oxidase polymorphisms on primate social behavior.
