Decomposed pairwise regression analysis of genetic and geographic distances reveals a metapopulation structure of stream-dwelling Dolly Varden charr
Decomposed pairwise regression analysis of genetic and geographic distances reveals a metapopulation structure of stream-dwelling Dolly Varden charr
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DOI：
10.1111/j.1365-294x.2006.03019.x
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发表时间：
2006-10-01
影响因子：
4.9
通讯作者：
Maekawa, Koji
中科院分区：
文献类型：
--
作者：
Koizumi, Itsuro;Yamamoto, Shoichiro;Maekawa, Koji
距离隔离通常通过分离所有成对群体组合的遗传距离和地理距离的相关性来检验。然而，这种方法可能会显着偏差，只有少数高度分化的人口和丢失的个人群体的信息。为了检测离群群体并研究每个群体的基因流和遗传漂变的相对强度，我们提出了一种分解的成对回归分析。这种分析被应用到描述的一维踏脚石系统的流居住多莉瓦登红点鲑（Salvelinus malma）。当对17个支流种群的所有对进行遗传距离和地理距离作图时，相关性显著但较弱（r（2）= 0.184）。根据回归残差的系统偏倚，然后根据Akaike的信息标准，确定了7个离群值群体。10个居群的最佳模型表现出较强的距离隔离模式（r（2）= 0.758），表明这些居群中基因流和遗传漂变之间存在平衡。每一个离群人群也进行了分析，绘制成对的遗传和地理距离对10个非离群人群，并归类为三种模式之一：强遗传漂变，遗传漂变与有限的基因流和高水平的基因流。这些分类通常与对每个种群的先验预测（物理障碍、种群规模、人为影响）相一致。结合遗传分析和野外观察，该河中的多莉瓦登似乎形成了一个大陆-岛屿或源-库集合种群结构。该方法的通用性将值得许多类型的空间遗传分析。
Isolation by distance is usually tested by the correlation of genetic and geographic distances separating all pairwise populations' combinations. However, this method can be significantly biased by only a few highly diverged populations and lose the information of individual population. To detect outlier populations and investigate the relative strengths of gene flow and genetic drift for each population, we propose a decomposed pairwise regression analysis. This analysis was applied to the well-described one-dimensional stepping-stone system of stream-dwelling Dolly Varden charr (Salvelinus malma). When genetic and geographic distances were plotted for all pairs of 17 tributary populations, the correlation was significant but weak (r(2) = 0.184). Seven outlier populations were determined based on the systematic bias of the regression residuals, followed by Akaike's information criteria. The best model, 10 populations included, showed a strong pattern of isolation by distance (r(2) = 0.758), suggesting equilibrium between gene flow and genetic drift in these populations. Each outlier population was also analysed by plotting pairwise genetic and geographic distances against the 10 nonoutlier populations, and categorized into one of the three patterns: strong genetic drift, genetic drift with a limited gene flow and a high level of gene flow. These classifications were generally consistent with a priori predictions for each population (physical barrier, population size, anthropogenic impacts). Combined the genetic analysis with field observations, Dolly Varden in this river appeared to form a mainland-island or source-sink metapopulation structure. The generality of the method will merit many types of spatial genetic analyses.