Landscape permeability and individual variation in a dispersal-linked gene jointly determine genetic structure in the Glanville fritillary butterfly

There is now clear evidence that species across a broad range of taxa harbour extensive heritable variation in dispersal. While studies suggest that this variation can facilitate demographic outcomes such as range expansion and invasions, few have considered the consequences of intraspecific variation in dispersal for the maintenance and distribution of genetic variation across fragmented landscapes. Here we examine how landscape characteristics and individual variation in dispersal combine to predict genetic structure using genomic and spatial data from the Glanville fritillary butterfly. We used linear and latent factor mixed models to identify the landscape features that best predict spatial sorting of alleles in the dispersal-related gene phosphoglucose isomerase (Pgi). We next used structural equation modeling to test if variation in Pgi mediated gene flow as measured by Fst at putatively neutral loci. In a year when the population was expanding following a large decline, individua...

现有明确证据表明，广泛类群（taxa）的物种均存在大量与扩散（dispersal）相关的可遗传变异（heritable variation）。尽管已有研究提示，这类变异可推动种群范围扩张（range expansion）、生物入侵（invasions）等种群动态结果（demographic outcomes），但极少有研究探讨扩散相关的种内变异（intraspecific variation）对破碎化景观（fragmented landscapes）中遗传变异（genetic variation）的维持与分布产生的影响。本研究以格兰维尔蛱蝶（Glanville fritillary butterfly）的基因组数据（genomic data）与空间数据（spatial data）为研究材料，探究景观特征与个体扩散变异如何共同作用以预测种群遗传结构。我们首先采用线性混合模型（linear mixed models）与潜变量混合模型（latent factor mixed models），筛选出可最佳预测扩散相关基因——磷酸葡萄糖异构酶（phosphoglucose isomerase, Pgi）的等位基因空间分异的景观特征。随后通过结构方程模型（structural equation modeling），检验Pgi基因变异是否会对推定中性位点（putatively neutral loci）的固定指数（Fixation index, Fst）所衡量的基因流（gene flow）产生介导作用。在种群经历大规模衰退后出现扩张的这一年，个体……