title: Sex-specific genetic structure and social organization in Central Asia: insights from a multi-locus study.
abstract: In the last two decades, mitochondrial DNA (mtDNA) and the non-recombining portion of the Y chromosome (NRY) have been extensively used in order to measure the maternally and paternally inherited genetic structure of human populations, and to infer sex-specific demography and history. Most studies converge towards the notion that among populations, women are genetically less structured than men. This has been mainly explained by a higher migration rate of women, due to patrilocality, a tendency for men to stay in their birthplace while women move to their husband's house. Yet, since population differentiation depends upon the product of the effective number of individuals within each deme and the migration rate among demes, differences in male and female effective numbers and sex-biased dispersal have confounding effects on the comparison of genetic structure as measured by uniparentally inherited markers. In this study, we develop a new multi-locus approach to analyze jointly autosomal and X-linked markers in order to aid the understanding of sex-specific contributions to population differentiation. We show that in patrilineal herder groups of Central Asia, in contrast to bilineal agriculturalists, the effective number of women is higher than that of men. We interpret this result, which could not be obtained by the analysis of mtDNA and NRY alone, as the consequence of the social organization of patrilineal populations, in which genetically related men (but not women) tend to cluster together. This study suggests that differences in sex-specific migration rates may not be the only cause of contrasting male and female differentiation in humans, and that differences in effective numbers do matter.
authors.affiliation: Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique UMR 5145, Université Paris 7, Eco-Anthropologie et Ethnobiologie, Musée de l'Homme, Paris, France. lsegurel@mnhn.fr
authors.forename: Laure
authors.initials: L
authors.lastname: Ségurel
authors.forename: Begoña
authors.initials: B
authors.lastname: Martínez-Cruz
authors.forename: Lluis
authors.initials: L
authors.lastname: Quintana-Murci
authors.forename: Patricia
authors.initials: P
authors.lastname: Balaresque
authors.forename: Myriam
authors.initials: M
authors.lastname: Georges
authors.forename: Tatiana
authors.initials: T
authors.lastname: Hegay
authors.forename: Almaz
authors.initials: A
authors.lastname: Aldashev
authors.forename: Firuza
authors.initials: F
authors.lastname: Nasyrova
authors.forename: Mark A
authors.initials: MA
authors.lastname: Jobling
authors.forename: Evelyne
authors.initials: E
authors.lastname: Heyer
authors.forename: Renaud
authors.initials: R
authors.lastname: Vitalis
mesh_terms: D000328:Adult; D001209:Asia, Central; D041322:Chromosomes, Human, Y / Q000235:genetics*; D003198:Computer Simulation; D004272:DNA, Mitochondrial / Q000235:genetics; D004641:Emigration and Immigration; D005260:Female; D005828:Genetics, Population; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D020641:Polymorphism, Single Nucleotide; D011157:Population Dynamics; D012737:Sex Factors; D012931:Social Environment
chemical_list: D004272:DNA, Mitochondrial