Moccetti Paolo, Bolland Jonathan D, Adams Colin E, Rodger Jessica R, Honkanen Hannele M, Newton Matthew, Lothian Angus J, Nunn Andy D, Joyce Domino A
Energy and Environment Institute University of Hull Hull UK.
Evolutionary and Ecological Genomics Group, School of Natural Sciences University of Hull Hull UK.
Ecol Evol. 2024 Dec 16;14(12):e70682. doi: 10.1002/ece3.70682. eCollection 2024 Dec.
Migratory species typically undertake demanding long-distance journeys, across different habitat types during which they are exposed to multiple natural and anthropogenic stressors. Mortality during migration is typically high and may be human induced. Understanding individual responses to these selection pressures is rarely attempted because of the challenges of relating individual phenotypic and genetic data to migration success. Here, we show distinct single nucleotide polymorphism (SNP) sets significantly differentiated between Atlantic salmon smolts making successful migrations to sea and those that failed to migrate, in two different rivers. In contrast, morphological variation was not diagnostic of migration success. Populations from each river were genetically distinct, and while different genes were possibly implicated in migration success in each river, they related to common biological processes (e.g., osmoregulation and immune and stress response). Given that migration failure should quickly purge polymorphism at selected SNPs from a population, the question of how genetic diversity in these populations is maintained is an important one. Standing genetic variation could be maintained by different life history strategies and/or environmentally driven balancing selection. Our work highlights the importance of preserving genetic diversity to ensure evolutionary resilience at the population level and has practical implications for management.
洄游物种通常要进行艰苦的长途迁徙，跨越不同的栖息地类型，在此期间它们会面临多种自然和人为压力源。迁徙过程中的死亡率通常很高，而且可能是人为导致的。由于将个体表型和遗传数据与迁徙成功联系起来存在挑战，因此很少有人尝试了解个体对这些选择压力的反应。在这里，我们展示了在两条不同河流中，成功洄游到大海的大西洋鲑幼鱼和未能洄游的幼鱼之间存在显著差异的单核苷酸多态性（SNP）集。相比之下，形态变异并不能诊断迁徙是否成功。每条河流的种群在基因上是不同的，虽然每条河流中可能有不同的基因与迁徙成功有关，但它们都与共同的生物学过程（如渗透调节、免疫和应激反应）相关。鉴于迁徙失败应该会迅速清除种群中选定SNP处的多态性，这些种群中遗传多样性如何得以维持是一个重要问题。持久的遗传变异可以通过不同的生活史策略和/或环境驱动的平衡选择来维持。我们的研究强调了保护遗传多样性以确保种群水平进化恢复力的重要性，并对管理具有实际意义。
