在分歧和人口基因组尺度上几乎中性理论的经验验证,使用144个胎盘哺乳动物基因组
M Bastian1, D Enard2, N Lartillot1
1Laboratoire de Biométrie et Biologie Evolutive, UMR5558, Université Lyon 1, Villeurbanne, France.
bioRxiv : the preprint server for biology
|December 25, 2025
概括
随机漂移影响基因组进化,近中性理论预测遗传多样性比率和有效人口规模 (Ne) 之间的负相关性. 这项研究为哺乳动物提供了第一个全球测试,将微观和宏观进化尺度与Ne.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.
- 人口遗传学 人口遗传学
背景情况:
- 随机漂移在基因组进化中发挥着重要作用,因为它限制了选择的有效性.
- 几乎中性理论认为,遗传多样性/分歧比率 (πN/πS,dN/dS) 和有效人口规模 (Ne) 之间存在负相关性.
- 之前的研究通常集中在微观或宏观进化尺度上,并使用生命史特征 (LHT) 作为Ne的代理,有效性有限.
研究的目的:
- 在哺乳动物的微观和宏观进化尺度上对近乎中性理论进行综合性测试.
- 验证使用LHT作为Ne的替代品,而不是直接测量遗传多样性的方法.
- 研究非同义词与同义词的多态/分歧比率与150种哺乳动物的有效种群大小之间的关系.
主要方法:
- 分析了来自150种哺乳动物的6000个正统基因.
- 从组装的双胞胎基因组中使用异构性 (πS) 评估微进化规模.
- 使用dN/dS比率和LHT进行评估的宏观进化规模,将它们与πS相关联.
主要成果:
- 在哺乳动物核基因组中观察到πN/πS和πS之间的关系,支持微进化规模的近乎中性预测.
- 在宏观进化尺度上证实了dN/dS和LHT之间的正相关性.
- 发现LHT和dN/dS与πS的相关性很弱,这表明LHT是Ne的合理代理.
结论:
- 这项研究为哺乳动物的进化时间表中几乎中性理论提供了第一个全面的测试.
- 结果表明,遗传多样性,分歧和生命历史特征都受有效人口大小 (Ne) 的影响.
- 这些发现支持了近中性理论的预测,并突出了Ne在基因组进化中的统一作用.
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