Institut des Sciences de l'Evolution de Montpellier, Unité Mixte de Recherche 5554, Centre National de la Recherche Scientifique, UMR 5554 CNRS, Université Montpellier 2, F-34095 Montpellier, France.
Institut des Sciences de l'Evolution de Montpellier, Unité Mixte de Recherche 5554, Centre National de la Recherche Scientifique, UMR 5554 CNRS, Université Montpellier 2, F-34095 Montpellier, France; Montpellier SupAgro, Unité Mixte de Recherche 1334 Amélioration Génétique et Adaptation des Plantes Méditerranéennes et Tropicales, F-34398 Montpellier, France.
Trends Genet. 2014 Jul;30(7):263-70. doi: 10.1016/j.tig.2014.05.002. Epub 2014 Jun 7.
In angiosperms (as in other species), GC content varies along and between genes, within a genome, and between genomes of different species, but the reason for this distribution is still an open question. Grass genomes are particularly intriguing because they exhibit a strong bimodal distribution of genic GC content and a sharp 5'-3' decreasing GC content gradient along most genes. Here, we propose a unifying model to explain the main patterns of GC content variation at the gene and genome scale. We argue that GC content patterns could be mainly determined by the interactions between gene structure, recombination patterns, and GC-biased gene conversion. Recent studies on fine-scale recombination maps in angiosperms support this hypothesis and previous results also fit this model. We propose that our model could be used as a null hypothesis to search for additional forces that affect GC content in angiosperms.
在被子植物（和其他物种一样）中，GC 含量在基因内和基因之间、一个基因组内以及不同物种的基因组之间都存在差异，但这种分布的原因仍未解决。禾本科基因组尤其引人注目，因为它们表现出强烈的基因 GC 含量双峰分布和大多数基因沿 5' - 3' 方向 GC 含量逐渐降低的陡峭梯度。在这里，我们提出了一个统一的模型来解释基因和基因组尺度上 GC 含量变化的主要模式。我们认为，GC 含量模式主要可以由基因结构、重组模式和 GC 偏向性基因转换之间的相互作用来决定。最近对被子植物精细尺度重组图谱的研究支持了这一假设，之前的结果也符合这一模型。我们提出，我们的模型可以作为一个零假设，用来寻找影响被子植物 GC 含量的其他因素。
