Patterns of selection on synonymous and nonsynonymous variants in Drosophila miranda
Patterns of selection on synonymous and nonsynonymous variants in Drosophila miranda
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DOI：
10.1534/genetics.104.033068
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发表时间：
2005-03-01
期刊：
影响因子：
3.3
通讯作者：
Charlesworth, B
中科院分区：
文献类型：
--
作者：
Bartolomé, C;Maside, X;Charlesworth, B
我们已经调查了一组常染色体和X连锁基因座的果蝇米兰达的同义和非同义变体的种内多态性和种间分歧的模式。D. Pseudobscura和D. affinis用于种间比较。结果表明纯化选择对非同义，多态性变体的作用。在同义多态性中，从优选密码子到非优选密码子的同义突变和GC到AT突变显著过量。在非编码位点的多态性中没有多余的GC到AT突变。这表明选择作用是为了维持偏好密码子的上升。间接证据表明，偏向于GC碱基对的基因转换也可能起作用。根据有效群体大小与选择和转换系数之和的乘积，估计选择和偏向基因转换的联合强度近似于0.65。
We have investigated patterns of within-species polymorphism and between-species divergence for synonymous and nonsynonymous variants at a set of autosomal and X-linked loci of Drosophila miranda. D. pseudoobscura and D. affinis were used for the between-species comparisons. The results suggest the action of purifying selection on nonsynonymous, polymorphic variants. Among synonymous polymorphisms, there is a significant excess of synonymous mutations from preferred to unpreferred codons and of GC to AT mutations. There was no excess of GC to AT mutations among polymorphisms at noncoding sites. This suggests that selection is acting to maintain the rise of preferred codons. Indirect evidence suggests that biased gene conversion in favor of GC base pairs may also be operating. The joint intensity of selection and biased gene conversion, in terms of the product of effective Population size and the sum of the selection and conversion coefficients, was estimated to be similar to 0.65.