Genomic signatures of local directional selection in a high gene flow marine organism; the Atlantic cod (Gadus morhua).
Genomic signatures of local directional selection in a high gene flow marine organism; the Atlantic cod (Gadus morhua).
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DOI：
10.1186/1471-2148-9-276
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发表时间：
2009-12-01
影响因子：
3.4
通讯作者：
Carvalho GR
中科院分区：
文献类型：
--
作者：
Nielsen EE;Hemmer-Hansen J;Poulsen NA;Loeschcke V;Moen T;Johansen T;Mittelholzer C;Taranger GL;Ogden R;Carvalho GR
海洋鱼类表现出低水平的遗传结构和相关的高水平的基因流，这表明进化轨迹较浅，当地种群之间的适应分歧可能有限或缺乏。本文研究了98个基因相关单核苷酸多态(SNPs)在大西洋鳕鱼(Gadus morhua L.)地方群体中的变异。在物种分布上。我们的全球基因组扫描分析确定了8个具有非常高统计支持的离群值基因座位，它们可能受到局部Deme的定向选择，或与正在选择的座位紧密连锁。同样，在大西洋中部和东部种群的区域南/北样带上，有7个基因座显示出强烈的遗传分化水平。群体之间的选择模式似乎相对广泛和复杂，即离群值基因座通常不仅与少数几个不同的当地群体中的一个有关。即使在北海和波罗的海人口之间有限的地理范围内，也有四个基因座显示出适应性进化的证据。对来自法罗群岛人群的存档耳石的DNA进行的时间基因组扫描分析表明，种群内变异在24年内是稳定的。探索性的景观遗传分析被用来阐明最有可能的环境因素的潜在影响，这些因素对当地适应的特征负责。我们发现，一些离群点的遗传变异与产卵时产卵场的温度和/或盐度条件的相关性比与地理距离本身的相关性更好。这些发现表明，尽管在大多数海鱼中发现了似乎高水平的基因流，但适应性种群分化确实可能是普遍存在的。因此，这些结果对于我们理解进化力量的总体相互作用，以及在气候和渔业引起的当地环境变化带来的进化压力迅速增加的情况下保护海洋生物多样性具有重要意义。
Marine fishes have been shown to display low levels of genetic structuring and associated high levels of gene flow, suggesting shallow evolutionary trajectories and, possibly, limited or lacking adaptive divergence among local populations. We investigated variation in 98 gene-associated single nucleotide polymorphisms (SNPs) for evidence of selection in local populations of Atlantic cod (Gadus morhua L.) across the species distribution. Our global genome scan analysis identified eight outlier gene loci with very high statistical support, likely to be subject to directional selection in local demes, or closely linked to loci under selection. Likewise, on a regional south/north transect of central and eastern Atlantic populations, seven loci displayed strongly elevated levels of genetic differentiation. Selection patterns among populations appeared to be relatively widespread and complex, i.e. outlier loci were generally not only associated with one of a few divergent local populations. Even on a limited geographical scale between the proximate North Sea and Baltic Sea populations four loci displayed evidence of adaptive evolution. Temporal genome scan analysis applied to DNA from archived otoliths from a Faeroese population demonstrated stability of the intra-population variation over 24 years. An exploratory landscape genetic analysis was used to elucidate potential effects of the most likely environmental factors responsible for the signatures of local adaptation. We found that genetic variation at several of the outlier loci was better correlated with temperature and/or salinity conditions at spawning grounds at spawning time than with geographic distance per se. These findings illustrate that adaptive population divergence may indeed be prevalent despite seemingly high levels of gene flow, as found in most marine fishes. Thus, results have important implications for our understanding of the interplay of evolutionary forces in general, and for the conservation of marine biodiversity under rapidly increasing evolutionary pressure from climate and fisheries induced changes in local environments.
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影响因子：
3.7
作者：
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通讯作者：
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通讯作者：
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作者：
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通讯作者：
Carvalho, GR
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作者：
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