Recently integrated Alu retrotransposons are essentially neutral residents of the human genome
Recently integrated Alu retrotransposons are essentially neutral residents of the human genome
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DOI：
10.1016/j.gene.2006.01.020
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发表时间：
2006-05-24
期刊：
影响因子：
3.5
通讯作者：
Batzer, Mark A.
中科院分区：
文献类型：
--
作者：
Cordaux, Richard;Lee, Jungnam;Batzer, Mark A.
Alu元件代表拷贝数最大的人类移动的元件家族。一个有争议的问题与Alu生物学和人类基因组进化的影响是选择压力是否影响Alu元素在大规模上。为了解决这个问题，我们分析了三个最年轻的已知人类Alu亚家族（Ya5a2，Ya8和Yb9）的基因组分布，以及它们在人群中的插入多态性状态，因为选择只能作用于多态性元件。我们的研究结果表明：（i）多态性和固定的最近整合的Alu元件发现于GC含量在统计学上不可区分的基因组区域中，和（ii）最近整合的Alu元件随机插入，而不管周围基因组DNA的GC含量。这些结果提供了强有力的证据表明，最近整合的“年轻”的Alu元素不会受到大规模的积极或消极的选择。因此，年轻的Alu元件可以被认为是人类基因组中基本上中性的居民。这些结果也意味着，选择性的过程，特别是针对铝元素可以排除作为铝元素的积累在GC丰富的区域的人类基因组的解释。(c)2006 Elsevier B.V.保留所有权利。
Alu elements represent the largest family of human mobile elements in copy number. A controversial issue with implications for both Alu biology and human genome evolution is whether selective pressures are affecting Alu elements on a large scale. To address this issue, we analyzed the genomic distribution of the three youngest known human Alu subfamilies (Ya5a2, Ya8 and Yb9) in conjunction with their insertion polymorphism status in the human population, since selection can only act on polymorphic elements. Our results indicate that: (i) polymorphic and fixed recently integrated Alu elements are found in genomic regions whose GC contents are statistically indistinguishable, and (ii) recently integrated Alu elements are inserted randomly, regardless of the GC content of the surrounding genomic DNA. These results provide strong evidence that recently integrated "young" Alu elements are not subject to positive or negative selection on a large scale. Therefore, young Alu elements can be regarded as essentially neutral residents of the human genome. These results also imply that selective processes specifically targeting Alu elements can be ruled out as explanations for the accumulation of Alu elements in GC-rich regions of the human genome. (c) 2006 Elsevier B.V. All rights reserved.