title: Assessing natural introgression in 2 biomedical model species, the rhesus macaque (Macaca mulatta) and the long-tailed macaque (Macaca fascicularis).
abstract: Rhesus macaque (Macaca mulatta) and long-tailed macaque (Macaca fascicularis) are the 2 most commonly used primate model species in biomedical sciences. Although morphological studies have revealed a weak hybridization at the interspecific contact zone, in the north of Indochina, a molecular study has suggested an ancient introgression from rhesus to long-tailed macaque into the Indo-Chinese peninsula. However, the gene flow between these 2 taxa has never been quantified using genetic data and theoretical models. In this study, we have examined genetic variation within and between the parapatric Chinese rhesus macaque and Indo-Chinese long-tailed macaque populations, using 13 autosomal, 5 sex-linked microsatellite loci and mitochondrial DNA sequence data. From these data, we assessed genetic structure and estimated gene flow using a Bayesian clustering approach and the "Isolation with Migration" model. Our results reveal a weak interspecific genetic differentiation at both autosomal and sex-linked loci, suggesting large population sizes and/or gene flow between populations. According to the Bayesian clustering, Chinese rhesus macaque is a highly homogeneous gene pool that contributes strongly to the current Indo-Chinese long-tailed macaque genetic makeup, whether or not current admixture is assumed. Coalescent simulations, which integrated the characteristics of the loci, pointed out 1) a higher effective population size in rhesus macaque, 2) no mitochondrial gene flow, and 3) unilateral and male-mediated nuclear gene flow of approximately 10 migrants per generation from rhesus to long-tailed macaque. These patterns of genetic structure and gene flow suggest extensive ancient introgression from Chinese rhesus macaque into the Indo-Chinese long-tailed macaque population.
authors.affiliation: the Université Paul Sabatier, Laboratoire Evolution et Diversité Biologique, UMR CNRS 5174, Toulouse cedex 9, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Bonhomme
authors.forename: Sergi
authors.initials: S
authors.lastname: Cuartero
authors.forename: Antoine
authors.initials: A
authors.lastname: Blancher
authors.forename: Brigitte
authors.initials: B
authors.lastname: Crouau-Roy
mesh_terms: D025041:Animal Migration / Q000502:physiology; D000818:Animals; D001499:Bayes Theorem; D002681:China; D019143:Evolution, Molecular; D005260:Female; D049810:Genetic Speciation; D005828:Genetics, Population; D006824:Hybridization, Genetic / Q000235:genetics*; D008252:Macaca fascicularis / Q000235:genetics*; D008253:Macaca mulatta / Q000235:genetics*; D008297:Male; D023421:Models, Animal; D012730:Sex Chromosomes; D014744:Vietnam