自然选择对子使用的宏观进化变化反映了tRNA池在芽的酵母子系中的进化
bioRxiv : the preprint server for biology
|April 28, 2025
概括
由于自然选择和突变偏差的变化,使用偏差 (CUB) 在不同物种之间存在差异. 由于tRNA基因拷贝数和修改的影响,tRNA基因池的进化影响了CUB和翻译效率.
科学领域:
- 微生物学 微生物学
- 进化生物学 进化生物学
- 遗传学 是一个遗传学.
背景情况:
- 同义代码在基因内使用不平等,这种现象被称为代码使用偏差 (CUB).
- CUB在不同物种之间存在差异,反映了微观进化力量的平衡,如自然选择和突变偏差.
- CUB与分子过程密切相关,特别是mRNA翻译.
研究的目的:
- 量化自然选择和突变偏差在芽酵母的每个codon基础上.
- 研究微观进化过程和分子机制如何相互作用形成CUB变异.
- 为了理解tRNA进化和自然选择在子使用中的联系.
主要方法:
- 采用人口遗传学模型来分析代码子使用偏差.
- 在327种芽酵母物种中量化了每种codon的自然选择和突变偏差.
- 与tRNA基因拷贝数和全基因组GC含量相关的CUB变异.
主要成果:
- 即使在密切相关的酵母之间,也观察到自然选择和突变偏差的显著变化.
- 在CUB上自然选择的变化与tRNA基因拷贝数的演变有关.
- 有证据表明,tRNA修饰表达影响了CUB上的自然选择,而不依赖tRNA基因拷贝数.
- 在tRNA基因拷贝数的变化往往与全基因组GC含量相关,表明与突变偏差的联系.
结论:
- 包括基因拷贝数和修改在内的tRNA池的进化是编码子使用中的自然选择的关键驱动因素.
- 微进化过程中的变化,例如突变偏差,可以影响tRNA池,并随后影响CUB.
- 这项研究阐明了分子机制和微观进化动力学如何相互作用,以塑造诸如子使用偏差等特征的宏观进化变异.
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