IPATIMUP, Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal.
PLoS One. 2012;7(11):e51103. doi: 10.1371/journal.pone.0051103. Epub 2012 Nov 30.
Recently admixed populations offer unique opportunities for studying human history and for elucidating the genetic basis of complex traits that differ in prevalence between human populations. Historical records, classical protein markers, and preliminary genetic data indicate that the Cape Verde islands in West Africa are highly admixed and primarily descended from European males and African females. However, little is known about the variation in admixture levels, admixture dynamics and genetic diversity across the islands, or about the potential of Cape Verde for admixture mapping studies. We have performed a detailed analysis of phenotypic and genetic variation in Cape Verde based on objective skin color measurements, socio-economic status (SES) evaluations and data for 50 autosomal, 34 X-chromosome, and 21 non-recombinant Y-chromosome (NRY) markers in 845 individuals from six islands of the archipelago. We find extensive genetic admixture between European and African ancestral populations (mean West African ancestry = 0.57, sd = 0.08), with individual African ancestry proportions varying considerably among the islands. African ancestry proportions calculated with X and Y-chromosome markers confirm that the pattern of admixture has been sex-biased. The high-resolution NRY-STRs reveal additional patterns of variation among the islands that are most consistent with differentiation after admixture. The differences in the autosomal admixture proportions are clearly evident in the skin color distribution across the islands (Pearson r = 0.54, P-value<2e-16). Despite this strong correlation, there are significant interactions between SES and skin color that are independent of the relationship between skin color and genetic ancestry. The observed distributions of admixture, genetic variation and skin color and the relationship of skin color with SES relate to historical and social events taking place during the settlement history of Cape Verde, and have implications for the design of association studies using this population.
最近的混合人群为研究人类历史以及阐明在不同人群中患病率不同的复杂特征的遗传基础提供了独特的机会。历史记录、经典蛋白质标记物和初步遗传数据表明，西非的佛得角群岛高度混合，主要由欧洲男性和非洲女性的后代组成。然而，人们对该群岛混合程度的变化、混合动态和遗传多样性知之甚少，也不知道佛得角在混合映射研究方面的潜力。我们基于客观肤色测量、社会经济地位（SES）评估以及来自群岛六个岛屿的 845 个人的 50 个常染色体、34 个 X 染色体和 21 个非重组 Y 染色体（NRY）标记的数据，对佛得角的表型和遗传变异进行了详细分析。我们发现欧洲和非洲祖先群体之间存在广泛的遗传混合（平均西非祖先=0.57，标准差=0.08），个体的非洲祖先比例在各岛屿之间差异很大。X 和 Y 染色体标记物计算的非洲祖先比例证实，混合模式存在性别偏倚。高分辨率 NRY-STRs 揭示了各岛屿之间的其他变异模式，这些模式与混合后的分化最为一致。各岛屿间的常染色体混合比例差异在肤色分布上非常明显（皮尔逊 r = 0.54，P 值<2e-16）。尽管存在这种强相关性，但 SES 和肤色之间存在显著的相互作用，与肤色和遗传祖先之间的关系无关。观察到的混合、遗传变异和肤色分布以及肤色与 SES 的关系与佛得角的定居历史上发生的历史和社会事件有关，并对使用该人群进行关联研究的设计具有影响。
