Genome-wide SNP analysis reveals a genetic basis for sea-age variation in a wild population of Atlantic salmon (Salmo salar)

Delaying sexual maturation can lead to larger body size and higher reproductive success, but carries an increased risk of death before reproducing. Classical life history theory predicts that trade-offs between reproductive success and survival should lead to the evolution of an optimal strategy in a given population. However, variation in mating strategies generally persists, and in general, there remains a poor understanding of genetic and physiological mechanisms underlying this variation. One extreme case of this is in the Atlantic salmon (Salmo salar), which can show variation in the age at which they return from their marine migration to spawn (i.e. their “sea age”). This results in large size differences between strategies, with direct implications for individual fitness. Here, we used an Illumina Infinium SNP-array to identify regions of the genome associated with variation in sea age in a large population of Atlantic salmon in Northern Europe, implementing individual-based geno...延迟性成熟可使个体体型更大、繁殖成功率更高，但同时会提升繁殖前死亡的风险。经典生活史理论预测，繁殖成功率与存活之间的权衡应会促使特定种群演化出最优策略。然而，交配策略的变异通常持续存在，且目前学界对该变异背后的遗传与生理机制仍知之甚少。这类变异的一个极端案例见于大西洋鲑（Atlantic salmon, *Salmo salar*），其从海洋洄游返回产卵的年龄存在差异，即所谓的“海龄”。这导致不同策略个体间体型差异显著，对个体适合度具有直接影响。本研究针对北欧的大型大西洋鲑种群，采用Illumina Infinium单核苷酸多态性（Single Nucleotide Polymorphism, SNP）芯片，鉴定与海龄变异相关的基因组区域，并实施了基于个体的基因分型……