Widespread Compensatory Evolution Conserves DNA-Encoded Nucleosome Organization in Yeast
Widespread Compensatory Evolution Conserves DNA-Encoded Nucleosome Organization in Yeast
复制标题
DOI：
10.1371/journal.pcbi.1001039
复制
发表时间：
2010-12-01
影响因子：
4.3
通讯作者：
Tanay, Amos
中科院分区：
文献类型：
--
作者：
Kenigsberg, Ephraim;Bar, Amir;Tanay, Amos
进化通过保存基因组信息来维持生物体的适应性。这被广泛认为涉及物种之间特定基因组位点的保守。许多基因组编码现在被认为是将来自多个基因组位置的小贡献整合到定量分散代码中，但这些代码的进化动力学仍然知之甚少。在这里，我们表明，在酵母中，定量影响核小体占用的序列的发展下，通过空间耦合的A/T-失去和A/T-获得取代保持异质水平的A+T含量的补偿动力学。进化模型结合酵母多态性的数据支持的想法，这些取代动态是弱选择的结果。这表明，补偿性进化，迄今为止被认为会影响特定群体的上位性连锁位点，如成对的RNA碱基，是一种普遍的现象，在酵母基因组中，影响大多数的基因间序列在it. The模型由此得出的建议，补偿是不可避免的进化时，保存数量和分散的基因组功能。
Evolution maintains organismal fitness by preserving genomic information. This is widely assumed to involve conservation of specific genomic loci among species. Many genomic encodings are now recognized to integrate small contributions from multiple genomic positions into quantitative dispersed codes, but the evolutionary dynamics of such codes are still poorly understood. Here we show that in yeast, sequences that quantitatively affect nucleosome occupancy evolve under compensatory dynamics that maintain heterogeneous levels of A+T content through spatially coupled A/T-losing and A/T-gaining substitutions. Evolutionary modeling combined with data on yeast polymorphisms supports the idea that these substitution dynamics are a consequence of weak selection. This shows that compensatory evolution, so far believed to affect specific groups of epistatically linked loci like paired RNA bases, is a widespread phenomenon in the yeast genome, affecting the majority of intergenic sequences in it. The model thus derived suggests that compensation is inevitable when evolution conserves quantitative and dispersed genomic functions.