Polymorphic analysis of hypervariable mimisatellite related to recombination hot spot

人类串联重复序列约占人类基因组的3%，并且(不包括卫星DNA)根据重复单位的大小和重复序列的总长度被分为两类。人类小卫星或可变数目串联重复序列(VNTR)基因座的重复单位长度从6个碱基到100多个碱基不等，排列的长度通常为千个碱基。人类富含GC的小卫星优先聚集在染色体重组熟练的亚端粒区域。一些小卫星基因座表现出很高的等位基因长度变异性。大多数小卫星基因座由两个或更多微妙不同的重复单位类型(小卫星变异重复)的异质阵列组成。到目前为止，所有人类高变小卫星的特征不仅在重复拷贝数(等位基因长度)上不同，而且在这些变异重复单元在阵列内的散布模式上也不同。这种内部变化为st…提供了一种强大的方法。更多的研究等位基因变异和突变的处理。通过小卫星变异重复(MVR)定位可以确定散布模式，并且揭示了比等位基因长度分析所能分辨的更多的变异性。等位基因大小分布显示，与北欧人相比，日本人保留了广泛的等位基因长度变异性，但等位基因明显较小。对92个日本等位基因进行了MVR-PCR分析。这些等位基因表现出多种多样的内部MVR结构，大多数等位基因在样本中只观察到一次。真实杂合度估计为99.95%，在日本人群中存在2000个不同的等位基因。点阵分析表明，在日本人和北欧人中可以识别出具有相同结构基序的相关等位基因组，并且这些组是群体特有的，没有任何日本和北欧等位基因之间显著相似的例子。因此，小卫星B6.7在日本和北欧人群中表现出巨大的等位基因变异性和快速的重复更新，为探索人类种群历史上最近发生的事件提供了新的谱系标记。我们还分析了日本人群中另一个高变量小卫星CEB1(D2S90)的特性。长度杂合度为85.0%，等位基因平均长度为69个重复。在小卫星两侧发现了一个新的单核苷酸多态(SMP)。不同等位基因的内部MVR结构不同，在重复序列中发现了新的花瓶替换/缺失，这表明CEB1也是日本人中变异最多的小卫星基因座之一。较少

Human tandem repeats account for about 3% of the human genome and (excluding satellite DNA) are classified into two groups according to the size of the repeat unit and the overall length of the repeat array. Human minisatellites or variable number tandem repeat (VNTR) loci have repeat units from 6 bp to more than 100 bp long depending on the locus, with arrays usually kilobases in length. Human GC-rich minisatellites are preferentially found clustered in the recombination-proficient subtelomeric regions of chromosomes. Some minisatellite loci show very high levels of allele length variability.Most minisatellite loci consist of heterogeneous arrays of two or more subtly different repeat unit types (minisatellite variant repeats). All human hypervariable minisatellites characterized to date vary not only in repeat copy number (allele length) but also in the interspersion pattern of these variant repeat units within the array. This internal variation provides a powerful approach to the st … More udy of allelic variation and processed of mutation. Interspersion patterns can be determined by minisatellite variant repeat (MVR) mapping and reveals far more variability than can be resolved by allele length analysis.We analyse minisatellite B6,7 locus in the Japanese population. Allele size distributions showed that Japanese retain extensive allele length variability but have significantly smaller alleles compared to north Europeans. Ninety-two Japanese alleles were further characterised by MVR-PCR. These alleles showed a wide variety of internal MVR structures with most alleles observed only once in the sample. The true heterozygosity is estimated at 99.95%, with well in express of 2000 different alleles existing in the Japanese population. Dot matrix analysis showed that groups of related alleles sharing structural motifs could be identified within Japanese and in north Europeans, and that these groups are population-specific with no examples of significant similarity between any Japanese and north European alleles. Minisatellite B6.7 therefore shows huge allele variability and fast repeat turnover in Japanese as well as north European populations, and provide novel lineage markers for exploring very recent events in human population history.We also anlaysed the properties of another hypervariable minisatellite CEB1 (D2S90) in the Japanese population. The length heterozygosity is observed at 85.0% and the average length of the alleles is 69 repeats. A new single nucleotide polymorphism (SMP) was found in the flanking the minisatellite. Internal MVR structure was different between alleles and new vase substitutions/deletions were found within repeats, which indicates CEB1 is also one of the most hypervariable minisatellite loci in Japanese. Less