自然选择对子使用的宏观进化变化反映了tRNA池在芽的酵母子族中的演变
Alexander L Cope1,2,3, Premal Shah1,3
1Department of Genetics, Rutgers University, Piscataway, NJ 08854.
概括
由于微观进化力量,使用偏差 (CUB) 在不同物种之间存在差异. 这项研究将tRNA基因拷贝数的变化和对自然选择驱动CUB的修改与芽酵母的自然选择联系起来.
科学领域:
- 进化生物学 进化生物学
- 基因组学就是基因组学.
- 分子生物学分子生物学
背景情况:
- 同义代码在基因组中使用不平等,这种现象被称为代码使用偏差 (CUB).
- 在不同物种中,CUB的差异很大,反映了适应性和非适应性微观进化过程之间的平衡.
- 了解CUB与分子/生物物理过程之间的联系对于破译进化机制至关重要.
研究的目的:
- 在Saccharomycotina芽酵母中量化自然选择和基因基因基因基因的突变偏差.
- 为了研究微观进化过程是如何在物种之间形成编码子使用偏差的.
- 建立微观进化变化与影响CUB的分子机制之间的联系.
主要方法:
- 采用人口遗传学模型来分析代码子使用偏差.
- 量化自然选择和基因突变偏差.
- 研究了tRNA基因拷贝数 (tGCN) 和tRNA修饰表达的演变.
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.
- 自然选择的跨物种变异与tRNA基因拷贝数 (tGCN) 的演变相关.
- 转基因RNA修饰表达的变化也影响了自然选择对配子的使用,独立于tGCN.
- 在tGCN的变化经常反映基因组范围的GC含量的变化,表明与突变偏差的联系.
结论:
- 通过tGCN和tRNA修饰的变化,tRNA池的进化直接影响自然选择对编码子的使用.
- 由tRNA池驱动的翻译效率的变化是将微演变过程与CUB联系起来的关键机制.
- 微观进化过程中的变化,包括在GC含量中反映的突变偏差,塑造分子机制,并最终影响宏观进化特征的变化.
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