Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, , 110 Shaffer Road, Santa Cruz, CA 95060, USA, Institute of Marine Sciences, University of California, , Santa Cruz, CA 95060, USA, Institute of Molecular Biology, University of Oregon, , Eugene, OR 97403, USA, Department of Animal Science, University of California, , One Shields Avenue, Davis, CA 95616, USA.
Proc Biol Sci. 2014 Mar 26;281(1783):20140012. doi: 10.1098/rspb.2014.0012. Print 2014 May 22.
Rapid adaptation to novel environments may drive changes in genomic regions through natural selection. Such changes may be population-specific or, alternatively, may involve parallel evolution of the same genomic region in multiple populations, if that region contains genes or co-adapted gene complexes affecting the selected trait(s). Both quantitative and population genetic approaches have identified associations between specific genomic regions and the anadromous (steelhead) and resident (rainbow trout) life-history strategies of Oncorhynchus mykiss. Here, we use genotype data from 95 single nucleotide polymorphisms and show that the distribution of variation in a large region of one chromosome, Omy5, is strongly associated with life-history differentiation in multiple above-barrier populations of rainbow trout and their anadromous steelhead ancestors. The associated loci are in strong linkage disequilibrium, suggesting the presence of a chromosomal inversion or other rearrangement limiting recombination. These results provide the first evidence of a common genomic basis for life-history variation in O. mykiss in a geographically diverse set of populations and extend our knowledge of the heritable basis of rapid adaptation of complex traits in novel habitats.
快速适应新环境可能通过自然选择推动基因组区域的变化。这些变化可能是特定于种群的，或者，如果该区域包含影响所选特征的基因或共同适应的基因复合物，则可能涉及多个种群中同一基因组区域的平行进化。定量和群体遗传学方法都已经确定了特定基因组区域与 Oncorhynchus mykiss 的溯河洄游（钢头）和居留（虹鳟）生活史策略之间的关联。在这里，我们使用来自 95 个单核苷酸多态性的基因型数据，并表明一个染色体 Omy5 的一个大区域的变异分布与多个虹鳟及其溯河洄游的钢头祖先的洄游障碍种群的生活史分化密切相关。相关的基因座处于强烈的连锁不平衡状态，表明存在染色体倒位或其他限制重组的重排。这些结果首次提供了在地理上多样化的虹鳟种群中生活史变异的共同基因组基础的证据，并扩展了我们对复杂特征在新栖息地中快速适应的可遗传性基础的认识。
