Santos C, Lima M, Montiel R, Angles N, Pires L, Abade A, Aluja Ma P
Unity of Anthropology, Department BABVE, Faculty of Sciences, Autonomous University of Barcelona, 08193 Bellaterra (Barcelona), Spain.
Ann Hum Genet. 2003 Sep;67(Pt 5):433-56. doi: 10.1046/j.1469-1809.2003.00031.x.
The Azores islands (Portugal), uninhabited when discovered by Portuguese navigators in the fifteenth century, are located in the Atlantic Ocean 1500 km from the European mainland. The archipelago is formed by nine islands of volcanic origin that define three geographical groups: Eastern (S. Miguel and Sta. Maria), Central (Terceira, Faial, Pico, Graciosa and S. Jorge) and Western (Flores and Corvo). To improve the genetic characterisation of the Azorean population, and to clarify some aspects related to the history of settlement, a study of mtDNA was conducted in the population of the archipelago. The HVRI region was sequenced and specific RFLPs were screened in 146 samples obtained from unrelated individuals with Azorean ancestry (50 from the Eastern group, 60 from the Central group, and 37 from the Western group). Samples were classified into haplogroups based on the information obtained from both sequencing and RFLP analysis. All the analyses performed support the idea that, in the whole group of islands, the majority of mtDNA lineages originated from the Iberian Peninsula, mainly from Portugal (mainland). However contributions from other European populations, especially from Northern Europe, cannot be disregarded. The values obtained for the various diversity parameters in the Azores archipelago indicate that the Azorean population, as a whole, does not exhibit the typical characteristics of an isolated population. The analysis of genetic data by groups of islands showed that the Western group exhibited particular features. The distribution of haplogroups in the Western group is very atypical, being significantly different from what is observed in the Eastern and Central groups. Furthermore, the diversity values are, in general, lower than those observed in other populations used for comparison. African haplogroups were found in all the groups of islands. Therefore the presence of Moorish and African slaves on the islands, as reported in historical sources, is supported by the mtDNA genetic data, especially in the Eastern group. The presence of Jews in the Central group is also supported by the mtDNA data. Neither historical nor genetic data (phylogeography of mtDNA) supports the idea of a differential settlement history for the Western group; however, it is represented in the phylogenies as an isolated branch. The effect of genetic drift, induced by the reduced population size since peopling occurred, has led to a very atypical distribution of haplogroups/haplotypes in this group of islands. We cannot ignore the influence of biodemographic and genetic processes, namely founder effect, genetic drift, migration, and even recent mutational events in the mtDNA lineages of the Azorean populations. Nevertheless, a great part of the variation in the Azorean mtDNA can be explained by the settlement history.
亚速尔群岛（葡萄牙）在15世纪被葡萄牙航海家发现时无人居住，位于距欧洲大陆1500公里的大西洋中。该群岛由九个火山起源的岛屿组成，分为三个地理区域：东部（圣米格尔岛和圣玛丽亚岛）、中部（特塞拉岛、法亚尔岛、皮科岛、格拉西奥萨岛和圣若热岛）和西部（弗洛雷斯岛和科尔武岛）。为了改进对亚速尔群岛居民的基因特征描述，并阐明与定居历史相关的一些方面，对该群岛的居民进行了线粒体DNA（mtDNA）研究。对146个样本的高变区I（HVRI）进行了测序，并筛选了特定的限制性片段长度多态性（RFLP），这些样本来自具有亚速尔群岛血统的无关个体（东部组50个，中部组60个，西部组37个）。根据测序和RFLP分析获得的信息将样本分类为单倍群。所有进行的分析都支持这样一种观点，即在整个群岛群体中，大多数mtDNA谱系起源于伊比利亚半岛，主要来自葡萄牙（大陆）。然而，其他欧洲人群，特别是北欧人群的贡献也不能忽视。在亚速尔群岛获得的各种多样性参数值表明，亚速尔群岛居民作为一个整体，并不表现出孤立群体的典型特征。按岛屿组对基因数据进行分析表明，西部组表现出特殊特征。西部组单倍群的分布非常不典型，与东部组和中部组观察到的情况有显著差异。此外，多样性值总体上低于用于比较的其他群体。在所有岛屿组中都发现了非洲单倍群。因此，历史资料中报道的该群岛上摩尔人和非洲奴隶的存在得到了mtDNA基因数据的支持，特别是在东部组。中部组中犹太人的存在也得到了mtDNA数据的支持。历史数据和基因数据（mtDNA系统地理学）都不支持西部组有不同定居历史的观点；然而，在系统发育树中它表现为一个孤立的分支。自有人居住以来人口规模减少所引发的遗传漂变效应，导致了该群岛组中单倍群/单倍型的非常不典型的分布。我们不能忽视生物人口学和遗传过程的影响，即奠基者效应、遗传漂变、迁移，甚至是亚速尔群岛居民mtDNA谱系中近期的突变事件。然而，亚速尔群岛mtDNA的很大一部分变异可以用定居历史来解释。
