Data from: Landscape models for nuclear genetic diversity and genetic structure in white-footed mice (Peromyscus leucopus)

Dramatic changes in the North American landscape over the last 12 000 years have shaped the genomes of the small mammals, such as the white-footed mouse (Peromyscus leucopus), which currently inhabit the region. However, very recent interactions of populations with each other and the environment are expected to leave the most pronounced signature on rapidly evolving nuclear microsatellite loci. We analyzed landscape characteristics and microsatellite markers of P. leucopus populations along a transect from southern Ohio to northern Michigan, in order to evaluate hypotheses about the spatial distribution of genetic heterogeneity. Genetic diversity increased to the north and was best approximated by a single-variable model based on habitat availability within a 0.5-km radius of trapping sites. Interpopulation differentiation measured by clustering analysis was highly variable and not significantly related to latitude or habitat availability. Interpopulation differentiation measured as FST values and chord distance was correlated with the proportion of habitat intervening, but was best explained by agricultural distance and by latitude. The observed gradients in diversity and interpopulation differentiation were consistent with recent habitat availability being the major constraint on effective population size in this system, and contradicted the predictions of both the postglacial expansion and core-periphery hypotheses.过去12000年间北美地貌的剧烈变化，塑造了现今栖息于该区域的小型哺乳动物的基因组，其中以白足鼠（Peromyscus leucopus）为典型代表。然而，种群间及其与环境间的新近互作，预计会在快速演化的核微卫星位点（nuclear microsatellite loci）上留下最为显著的遗传印记。为检验关于遗传异质性空间分布的相关假说，我们针对从俄亥俄州南部至密歇根州北部的样带上的白足鼠种群，分析了其景观特征与微卫星标记。研究结果显示，遗传多样性向北递增，且最优拟合模型为仅基于捕集位点0.5公里半径范围内栖息地可获得性的单变量模型。通过聚类分析测得的种群间分化程度变异性极高，且与纬度或栖息地可获得性无显著相关性。以FST值与弦距离（chord distance）衡量的种群间分化，与栖息地阻隔比例呈相关性，但最优解释因子为农业间隔距离与纬度。本研究观测到的多样性与种群间分化梯度，与“近期栖息地可获得性是该系统中有效种群大小的主要限制因素”这一结论相符，且与冰期后扩张假说以及核心-边缘假说的预测均相悖。