Genome-wide signatures of convergent evolution in echolocating mammals.
Genome-wide signatures of convergent evolution in echolocating mammals.
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进化通常被认为是通过基因、蛋白质和最终表型的差异来进行的。然而，由于相似的选择压力，相似的性状也可能在不相关的分类群中收敛地进化。适应性表型收敛在自然界中广泛存在，最近来自几个基因的结果表明，这种现象足够强大，也可以在序列水平上驱动循环进化。在发生同型替换的地方，这些长期以来一直被认为是中性过程的结果。然而，最近的研究表明，利用模拟并行进化的统计方法，可以在脊椎动物中检测到适应性收敛序列进化，尽管不同属之间跨基因组发生序列收敛的程度尚不清楚。在这里，我们分析了具有独立进化的回声定位的哺乳动物的基因组序列数据，并首次表明收敛并不是一个罕见的过程，仅限于少数几个座位，而是广泛、连续分布的，并且通常是由自然选择作用于每个座位上的少数几个部位所驱动的。对22种哺乳动物(包括4个新的蝙蝠基因组)2326个同源编码基因序列中805,053个氨基酸的收敛序列进化进行了系统分析，发现在近200个基因座上存在与收敛一致的特征。蝙蝠和海豚之间强烈而重要的融合支持在许多与听力或耳聋有关的基因中被发现，这与回声定位的参与是一致的。令人惊讶的是，我们还在许多与视觉有关的基因中发现了趋同：许多感觉基因的趋同信号与自然选择的强度密切相关。首次尝试检测跨不同分类群的全基因组收敛序列进化，揭示了这一现象比之前认识到的要普遍得多。
Evolution is typically thought to proceed through divergence of genes, proteins, and ultimately phenotypes. However, similar traits might also evolve convergently in unrelated taxa due to similar selection pressures. Adaptive phenotypic convergence is widespread in nature, and recent results from a handful of genes have suggested that this phenomenon is powerful enough to also drive recurrent evolution at the sequence level. Where homoplasious substitutions do occur these have long been considered the result of neutral processes. However, recent studies have demonstrated that adaptive convergent sequence evolution can be detected in vertebrates using statistical methods that model parallel evolution although the extent to which sequence convergence between genera occurs across genomes is unknown. Here we analyse genomic sequence data in mammals that have independently evolved echolocation and show for the first time that convergence is not a rare process restricted to a handful of loci but is instead widespread, continuously distributed and commonly driven by natural selection acting on a small number of sites per locus. Systematic analyses of convergent sequence evolution in 805,053 amino acids within 2,326 orthologous coding gene sequences compared across 22 mammals (including four new bat genomes) revealed signatures consistent with convergence in nearly 200 loci. Strong and significant support for convergence among bats and the dolphin was seen in numerous genes linked to hearing or deafness, consistent with an involvement in echolocation. Surprisingly we also found convergence in many genes linked to vision: the convergent signal of many sensory genes was robustly correlated with the strength of natural selection. This first attempt to detect genome-wide convergent sequence evolution across divergent taxa reveals the phenomenon to be much more pervasive than previously recognised.
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影响因子：
64.8
作者：
Clark, Andrew G.;Eisen, Michael B.;MacCallum, Iain
通讯作者：
MacCallum, Iain
影响因子：
10.7
作者：
Castresana, J
通讯作者：
Castresana, J
影响因子：
14.9
作者：
Kanehisa M;Goto S;Sato Y;Furumichi M;Tanabe M
通讯作者：
Tanabe M
影响因子：
3.9
作者：
Bielawski, JP;Yang, ZH
通讯作者：
Yang, ZH
DOI：
10.1073/pnas.0914625107
发表时间：
2010-05-11
影响因子：
11.1
作者：
Hancock, Angela M.;Witonsky, David B.;Di Rienzo, Anna
通讯作者：
Di Rienzo, Anna