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序列进化的复杂模型改善适合性,但不是基因树不一致性,为四足动物线粒基因组
Benjamin S Toups1, Robert C Thomson2, Jeremy M Brown1
1Department of Biological Sciences and Museum of Natural Science, Louisiana State University, 202 Life Sciences Bldg, Baton Rouge, LA 70803, USA.
Systematic biology
|October 11, 2024
概括
线粒体DNA中的基因树不一致性可能不仅仅来自生物过程. 即使有了改进的进化模型,显著的基因树变异仍然存在,加深了"Mito-Phylo悖论".
科学领域:
- 人类遗传学 是一个学科.
- 分子进化分子进化
- 生物信息学是一种生物信息学.
背景情况:
- 基因树的不一致性在基因组学数据中很常见,通常归因于生物学因素.
- 之前对四足动物线粒体基因组的研究发现了高基因树不一致性,即使控制了生物变异.
- 这项先前的工作表明,不充分的序列进化模型导致了观察到的不一致.
研究的目的:
- 为了研究更复杂的序列进化模型是否可以减少线粒体数据中的基因树异调.
- 测试整合异质基因 (特定地点速率变化) 和密码体特异性进化模式对基因树推断的影响.
- 为了进一步探索持续基因树不一致的原因,称为"米托-菲洛悖论".
主要方法:
- 对四足动物线粒体基因组数据集的分析.
- 应用了两个先进的序列进化模型:一个共变子模型 (用于异质性) 和一个分区模型 (用于子位置变化).
- 将这些先进模型推断出的基因树矛盾水平与以前使用的更简单模型进行比较.
主要成果:
- 协变模型和分区模型都比先前研究中使用的模型更好地适应序列数据.
- 随着数据集的大小的增加,共变量模型一直是首选的.
- 尽管改进了模型适合性,但这两种先进的模型仍然推断出高度不一致的线粒体基因树.
结论:
- 更复杂和生物学上更现实的序列进化模型可以改善数据的匹配性,但不能完全解决线粒体数据中的基因树不一致性.
- 持续高水平的基因树不一致,即使有更好的模型,表明生物因素确实可能是一个重要的贡献者,重新开启了对"米托-菲洛悖论"的调查.
- 需要进一步的研究来协调观察到的不一致性与进化过程和模型充分性.
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