GEOGRAPHICAL STRUCTURING IN THE MTDNA OF ITALIANS
GEOGRAPHICAL STRUCTURING IN THE MTDNA OF ITALIANS
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DOI：
10.1073/pnas.92.20.9171
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发表时间：
1995-09-26
影响因子：
11.1
通讯作者：
SCOZZARI, R
中科院分区：
文献类型：
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作者：
BARBUJANI, G;BERTORELLE, G;SCOZZARI, R
用两种不同的空间自相关方法研究了12个意大利样本（1072个个体）mtDNA变异的地理模式。对12种限制性变体的频率的单独分析显示了南北差异、撒丁岛和大陆人群之间的差异以及距离隔离的影响。最近开发的自相关统计总结分子相似性在所有网站（AIDA; DNA分析的自相关指数）证实了存在一个倾斜模式;随机对单倍型之间的差异往往会增加与他们的地理距离。然而，基因多样性的分区显示，大多数变异发生在种群内，而种群之间的差异很小（G（ST）= 0.057）。当将12个样本的数据汇总时，（多态位点数和成对个体间的平均序列差异）在中性条件下并不表现出预期的行为。倾斜模式、Tajima检验和模拟实验的存在都表明，在意大利和西西里，种群规模迅速增加，但在撒丁岛不一定如此。成对序列差异在意大利半岛（不包括撒丁岛）的分布允许8000和20,500年前之间的人口增长的暂定位置。这些日期是一致的考古学估计两个不同的扩张过程，发生，分别在新石器时代和旧石器时代的最后一次冰期后，相反，没有遗传证据表明，这种过程对撒丁岛人口产生了重大影响。
Geographical patterns of mtDNA variation were studied in 12 Italian samples (1072 individuals) by two different spatial autocorrelation methods. Separate analyses of the frequencies of 12 restriction morphs show North-South dines, differences between Sardinia and the mainland populations, and the effects of isolation by distance. A recently developed autocorrelation statistic summarizing molecular similarity at all sites (AIDA; autocorrelation index for DNA analysis) confirms the presence of a clinal pattern; differences between random pairs of haplotypes tend to increase with their geographical distance. The partition of gene diversity, however, reveals that most variability occurs within populations, whereas differences between populations are minor (G(ST) = 0.057). When the data from the 12 samples are pooled, two descriptors of genetic variability (number of polymorphic sites and average sequence difference between pairs of individuals) do not behave as expected under neutrality, The presence of clinal patterns, Tajima's tests, and a simulation experiment agree in suggesting that population sizes in creased rapidly in Italy and Sicily but not necessarily so in Sardinia, The distribution of pairwise sequence differences in the Italian peninsula (excluding Sardinia) permits a tentative location of the demographic increase between 8000 and 20,500 years ago. These dates are consistent with archaeological estimates of two distinct;expansion processes, occurring, respectively, in the Neolithic and after the last glacial maximum in the Paleolithic, Conversely, there is no genetic evidence that such processes have had a major impact on the Sardinian population.