Department of Abiotic Stress, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia 46022, Spain.
Systems Biology of Molecular Interactions and Regulation Department, Institute for Integrative Systems Biology (I2SysBio), Consejo Superior de Investigaciones, Científicas-Universitat de Valencia (CSIC-UV), Valencia 46980, Spain.
DNA Res. 2017 Dec 1;24(6):559-570. doi: 10.1093/dnares/dsx025.
Gene duplication is an important source of novelties and genome complexity. What genes are preserved as duplicated through long evolutionary times can shape the evolution of innovations. Identifying factors that influence gene duplicability is therefore an important aim in evolutionary biology. Here, we show that in the yeast Saccharomyces cerevisiae the levels of gene expression correlate with gene duplicability, its divergence, and transcriptional plasticity. Genes that were highly expressed before duplication are more likely to be preserved as duplicates for longer evolutionary times and wider phylogenetic ranges than genes that were lowly expressed. Duplicates with higher expression levels exhibit greater divergence between their gene copies. Duplicates that exhibit higher expression divergence are those enriched for TATA-containing promoters. These duplicates also show transcriptional plasticity, which seems to be involved in the origin of adaptations to environmental stresses in yeast. While the expression properties of genes strongly affect their duplicability, divergence and transcriptional plasticity are enhanced after gene duplication. We conclude that highly expressed genes are more likely to be preserved as duplicates due to their promoter architectures, their greater tolerance to expression noise, and their ability to reduce the noise-plasticity conflict.
基因复制是新特性和基因组复杂性的一个重要来源。在漫长的进化过程中，哪些基因能够被复制保留下来，会影响创新的进化。因此，确定影响基因可复制性的因素是进化生物学的一个重要目标。在这里，我们表明，在酵母酿酒酵母中，基因表达水平与基因可复制性、其分化和转录可塑性相关。在复制之前高表达的基因比低表达的基因更有可能作为复制基因保留更长的进化时间和更广泛的系统发育范围。表达水平较高的复制基因在其基因拷贝之间表现出更大的分化。含有 TATA 序列的启动子富集了表达分化较高的基因。这些复制基因还表现出转录可塑性，这似乎与酵母对环境胁迫的适应起源有关。虽然基因的表达特性强烈影响其可复制性，但分化和转录可塑性在基因复制后得到增强。我们的结论是，由于其启动子结构、对表达噪声的更大容忍度以及降低噪声-可塑性冲突的能力，高表达的基因更有可能被保留为复制基因。
