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在动物线粒体基因组中,从放松选择中解脱正选择
The American naturalist
|October 4, 2023
概括
分子进化研究经常误解高非同义词到同义词的替代率比率 (dN/dS). 放松的净化选择,而不仅仅是积极的选择,可以导致高dN/dS,需要对动物线粒体DNA进行仔细分析.
科学领域:
- 分子进化分子进化
- 人口遗传学 人口遗传学
- 生物信息学是一种生物信息学.
背景情况:
- 较高的非同义词到同义词替代率比率 (dN/dS) 通常被用作分子进化中积极选择的指标.
- 然而,放松的净化选择也可能导致dN/dS比率的增加,在解释中产生模两可.
- 区分积极选择和放松的净化选择对于理解进化过程至关重要.
研究的目的:
- 重新评估动物线粒体DNA (mtDNA) 中dN/dS比率升高的案例研究.
- 测试有关驱动这些高比率的选择性机制的假设.
- 研究分子进化信号的解释中的潜在混因素.
主要方法:
- 分析了七项已发表的案例研究,涉及动物mtDNA中dN/dS比率升高.
- 观察到的dN/dS模式与拟议的选择性机制 (例如,失能,生理适应) 的比较.
- 在进化假设的背景下对分子数据的批判性评估.
主要成果:
- 在一些案例研究中,高dN/dS比率并没有与预测的选择性压力有关.
- 证据有时支持放松的净化选择作为原因,与最初的假设相反.
- 与mtDNA相关的能量假设的解释经常被其他选择性力量所混.
结论:
- 对单个分子信号的过度解释,例如dN/dS比率升高,可能导致关于选择的不准确结论.
- 仔细考虑替代进化机制,特别是放松净化选择,是必不可少的.
- 未来的研究应该采用强大的方法来解开不同类型的对线粒体基因组起作用的选择.
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