Nucleotide polymorphism and linkage disequilibrium in wild populations of the partial selfer Caenorhabditis elegans
Nucleotide polymorphism and linkage disequilibrium in wild populations of the partial selfer Caenorhabditis elegans
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DOI：
10.1534/genetics.105.048207
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发表时间：
2006-01-01
期刊：
影响因子：
3.3
通讯作者：
Cutter, AD
中科院分区：
文献类型：
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作者：
Cutter, AD
要了解不同进化力量对生物体基因组的相对贡献，需要准确描述自然种群内和种群间的遗传变异模式。为此，我报告了118株秀丽隐杆线虫的6个位点的核苷酸多态性的调查。这些菌株来源于法国、德国几个地区的野生种群和苏格兰的新地点，以及储备中心分离株。沉默网站多样性的整体水平低，这种自我繁殖的物种，平均0.2%，在欧洲样本和0.3%的全球人口之间。人口结构是存在的，尽管缺乏关联的序列与地理，和移民似乎发生在所有的地理尺度。连锁不平衡在C.线虫的基因组，甚至在染色体之间延伸。然而，重组是明确存在于多态性的模式，表明异交是一个罕见的，但重要的，在这个物种的祖先功能。与数据一致的异交率的范围推断从连锁不平衡，使用“分散”的样本代表收集阶段的合并过程中细分的人口。我建议，在这个物种的遗传变异主要是由人口细分，由于自花受精加上长距离和短距离的迁移亚群之间的形状。
An understanding of the relative contributions of different evolutionary forces on an organism's genome requires an accurate description of the patterns of genetic variation within and between natural populations. To this end, I report a survey of nucleotide polymorphism in six loci from 118 strains of the nematode Caenorhabditis elegans. These strains derive from wild populations of several regions within France, Germany, and new localities in Scotland, in addition to stock center isolates. Overall levels of silent-site diversity are low within and between populations of this self-fertile species, averaging 0.2% in European samples and 0.3% worldwide. Population structure is present despite a lack of association of sequences with geography, and migration appears to occur at all geographic scales. Linkage disequilibrium is extensive in the C. elegans genome, extending even between chromosomes. Nevertheless, recombination is clearly present in the pattern of polymorphisms, indicating that outcrossing is an infrequent, but important, feature in this species ancestry. The range of outcrossing rates consistent with the data is inferred from linkage disequilibrium, using "scattered" samples representing the collecting phase of the coalescent process in a subdivided population. I propose that genetic variation in this species is shaped largely by population subdivision due to self-fertilization coupled with long- and short-range migration between subpopulations.