Recombination Yet Inefficient Selection along the Drosophila melanogaster Subgroup's Fourth Chromosome
Recombination Yet Inefficient Selection along the Drosophila melanogaster Subgroup's Fourth Chromosome
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DOI：
10.1093/molbev/msp291
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发表时间：
2010-04-01
影响因子：
10.7
通讯作者：
Long, Manyuan
中科院分区：
文献类型：
--
作者：
Arguello, J. Roman;Zhang, Yue;Long, Manyuan
进化遗传学的一个中心目标是理解造成物种内部和物种之间观察到的变异的力量。理论和经验研究表明，基因重组通过破坏核苷酸位点之间的连接，从而使它们能够独立地发挥作用，并使选择力有效地作用于它们，从而促成了这种变异。果蝇的第四条染色体被认为没有或非常低的重组率，一直是研究这些效应的重要模型。尽管以前的努力，关于重组的程度和选择作用于它的主要模式的中心问题仍然是开放的。为了更全面地检验关于重组及其对沿着第四条染色体选择的潜在影响的假设，我们对来自黑腹果蝇D. simulans和D.日本料理。这些数据，沿着与可用的外群序列，表明重组是低的，但显着大于零的三个物种。尽管存在重组，但有强有力的证据表明，其频率足够低，使选择相对低效。放松约束的特征可以在多态性和分歧水平上检测到。
A central goal of evolutionary genetics is an understanding of the forces responsible for the observed variation, both within and between species. Theoretical and empirical work have demonstrated that genetic recombination contributes to this variation by breaking down linkage between nucleotide sites, thus allowing them to behave independently and for selective forces to act efficiently on them. The Drosophila fourth chromosome, which is believed to experience no-or very low-rates of recombination has been an important model for investigating these effects. Despite previous efforts, central questions regarding the extent of recombination and the predominant modes of selection acting on it remain open. In order to more comprehensively test hypotheses regarding recombination and its potential influence on selection along the fourth chromosome, we have resequenced regions from most of its genes from Drosophila melanogaster, D. simulans, and D. yakuba. These data, along with available outgroup sequence, demonstrate that recombination is low but significantly greater than zero for the three species. Despite there being recombination, there is strong evidence that its frequency is low enough to have rendered selection relatively inefficient. The signatures of relaxed constraint can be detected at both the level of polymorphism and divergence.