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促进大西洋鱼生态适应的超基因的起源和维持

Minal Jamsandekar¹, Mafalda S Ferreira², Mats E Pettersson²

¹Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, USA.

Nature communications

|October 23, 2024

概括

大西洋鱼具有与适应相关的大量染色体逆转. 这些由子宫外再组合形成的反转,通过净化选择来维持,防止遗传负载积累.

科学领域:

进化遗传学的进化遗传学
人口基因组学是人口的基因组学.
海洋生物学海洋生物学

背景情况:

染色体逆转与局部适应有关,但其形成和维持机制尚未完全理解.
大西洋鱼 (Clupea harengus) 呈现出大量的染色体反转,与它们在北大西洋分布的不同水温的适应有关.

研究的目的:

研究大西洋鱼中四个兆基大小的染色体反转的形成,维持和进化影响.
确定这些反转的断点坐标和周围结构变化.
了解这些逆转在局部适应和基因流动中的作用.

主要方法:

利用大型基因组数据集,结合长读和短读测序.
确定了四个兆基大小的反转的断点坐标.
分析了围绕反转的结构变化.
在反转等位基因中研究基因流和遗传负载.

主要成果:

假设的反转是通过侧边重复序列之间的异位重组形成的.
约定时间的反转超过100万年,起源于从太平洋鱼分裂后.
在所有四个位置上观察到反转等位基因之间广泛的基因流动.
证明有效的净化选择,防止遗传负载积累,这是由于大量的有效种群规模和常见的相反同胞体.

结论:

大西洋鱼中的四个兆基大小的反转是古老的,是由异胎性重组形成的,并由强烈的净化选择维持.
这些逆转在局部适应温度梯度方面发挥着重要作用.
尽管基因流动,遗传负载是最小的,允许在物种分布的逆转等位基因的稳定共存.

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