The extent of linkage disequilibrium in Arabidopsis thaliana
The extent of linkage disequilibrium in Arabidopsis thaliana
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DOI：
10.1038/ng813
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发表时间：
2002-02-01
期刊：
影响因子：
30.8
通讯作者：
Weigel, D
中科院分区：
文献类型：
--
作者：
Nordborg, M;Borevitz, JO;Weigel, D
连锁不平衡（LD）是指等位基因在单倍型中的非随机分布，长期以来一直是群体遗传学家感兴趣的问题。最近，基因组多态性数据的快速增加的可用性激发了对LD作为精细定位工具的兴趣，特别是对于人类疾病基因座（1）。在这种情况下，LD的染色体范围是至关重要的，因为它决定了要检测到关联的图谱必须有多密集，相反，它限制了基因座的定位精度（2）。拟南芥由于其高度的自交，预计具有异常广泛的LD（3）。几项多态性研究发现，个别基因座内存在非常强的LD，但也有一些重组的证据（4-6）。在这里，我们调查的模式，LD在基因组规模和显示，在全球样本中，LD衰减约1厘米，或250 kb。我们还表明，LD在当地人口可能比全球人口强得多，大概是创始人事件的结果。相对高水平的多态性和广泛的单倍型结构的组合预示着在A. thaliana.
Linkage disequilibrium (LD), the nonrandom occurrence of alleles in haplotypes, has long been of interest to population geneticists. Recently, the rapidly increasing availability of genomic polymorphism data has fueled interest in LD as a tool for fine-scale mapping, in particular for human disease loci(1). The chromosomal extent of LD is crucial in this context, because it determines how dense a map must be for associations to be detected and, conversely, limits how finely loci may be mapped(2). Arabidopsis thaliana is expected to harbor unusually extensive LD because of its high degree of selfing(3). Several polymorphism studies have found very strong LD within individual loci, but also evidence of some recombination(4-6). Here we investigate the pattern of LD on a genomic scale and show that in global samples, LD decays within approximately 1 cM, or 250 kb. We also show that LD in local populations may be much stronger than that of global populations, presumably as a result of founder events. The combination of a relatively high level of polymorphism and extensive haplotype structure bodes well for developing a genome-wide LD map in A. thaliana.