二次接触,内进性杂交,和基因组稳定在杆背
Xueyun Feng1,2, Juha Merilä1,3, Ari Löytynoja2
1Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki 00014, Finland.
Molecular biology and evolution
|February 17, 2024
概括
在自然界中杂交是常见的,但其遗传后果是复杂的. 这项研究表明,虽然负选择往往会去除内进化的DNA,但在某些区域,鱼表现出适应性内进化.
科学领域:
- 进化生物学是进化的生物学.
- 基因组学就是基因组学.
- 人口遗传学 人口遗传学
背景情况:
- 杂交是一种重要的进化力量,但杂交后的基因组动力学仍然不完全理解.
- 最近的研究表明,杂交结果有一定的可预测性,但关于对内进变异的选择压力仍然存在大量的不确定性.
- 波罗的海提供了一个独特的系统,用于研究不同鱼类谱系之间的二次接触和内侵入.
研究的目的:
- 调查波罗的海两种不同的9脊鱼 (Pungitius pungitius) 血统之间的遗传内进的模式和选择性压力.
- 为了确定选择如何在不同的基因组元素 (例如,功能区域,促进器) 中因内进化而变化.
- 确定适应性内侵的证据及其在适应当地环境条件中的潜在作用.
主要方法:
- 来自不同波罗的海血统的9条杆的全面全基因组测序.
- 对基因内进化模式和整个基因组的选择强度的分析.
- 确定正或负选择下的基因组区域,包括促进和功能重要区域.
- 与二次接触区域相对的选择强度的地理分析.
主要成果:
- 侵入的强度和方向在基因组元素之间有很大的差异,功能区域显示了减少的侵入,促进器显示了丰富.
- 观察到对内向变异的负面选择的一般趋势,特别是在二次接触区域附近强烈.
- 特定的基因组区域表现出内向变异的丰富,具有可检测的选择足迹,表明适应性内向.
- 对功能变化的选择随着与最初接触区域的距离越来越远而减弱.
结论:
- 内向变化的稳定是一个复杂的,多阶段的过程,受到负面和正面选择的影响.
- 尽管存在消极选择的普遍性,但适应性内向变化的证据表明,内向变种可以促进适应新环境,如波罗的海.
- 了解这些复杂的基因组过程对于预测杂交种群的进化轨迹至关重要.
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