Data from: Genetic connectivity among swarming sites in the wide ranging and recently declining little brown bat (Myotis lucifugus)

Characterizing movement dynamics and spatial aspects of gene flow within a species permits inference on population structuring. As patterns of structuring are products of historical and current demographics and gene flow, assessment of structure through time can yield an understanding of evolutionary dynamics acting on populations that are necessary to inform management. Recent dramatic population declines in hibernating bats in eastern North America from white-nose syndrome have prompted the need for information on movement dynamics for multiple bat species. We characterized population genetic structure of the little brown bat, Myotis lucifugus, at swarming sites in southeastern Canada using 9 nuclear microsatellites and a 292-bp region of the mitochondrial genome. Analyses of FST, ΦST, and Bayesian clustering (STRUCTURE) found weak levels of genetic structure among swarming sites for the nuclear and mitochondrial genome (Global FST = 0.001, P < 0.05, Global ΦST = 0.045, P < 0.01, STRUCTURE K = 1) suggesting high contemporary gene flow. Hierarchical AMOVA also suggests little structuring at a regional (provincial) level. Metrics of nuclear genetic structure were not found to differ between males and females suggesting weak asymmetries in gene flow between the sexes. However, a greater degree of mitochondrial structuring does support male-biased dispersal long term. Demographic analyses were consistent with past population growth and suggest a population expansion occurred from approximately 1250 to 12,500 BP, following Pleistocene deglaciation in the region. Our study suggests high gene flow and thus a high degree of connectivity among bats that visit swarming sites whereby mainland areas of the region may be best considered as one large gene pool for management and conservation.

对物种内基因流的运动动态与空间特征进行表征，可为种群结构的推断提供依据。由于种群结构模式是历史与当前种群动态及基因流共同作用的产物，通过时间维度解析种群结构，能够明确作用于种群的进化动态，相关结果可为物种管理提供必要的科学支撑。北美东部的冬眠蝙蝠种群因白鼻综合征（white-nose syndrome）出现了近期的急剧下降，这促使学界亟需获取多种蝙蝠的运动动态相关信息。本研究以加拿大东南部的集群栖息位点为研究对象，利用9个核微卫星（nuclear microsatellites）标记以及一段292bp的线粒体基因组（mitochondrial genome）区域，分析了小棕蝠（Myotis lucifugus）的种群遗传结构。对FST、ΦST以及贝叶斯聚类分析（STRUCTURE）的结果显示，核基因组与线粒体基因组在集群栖息位点间仅存在微弱的遗传结构（全局FST=0.001，P<0.05；全局ΦST=0.045，P<0.01；STRUCTURE分析最优聚类数K=1），表明当前存在较高的基因流水平。分层分子方差分析（hierarchical AMOVA）同样显示，区域（省级）尺度下几乎不存在种群结构。核遗传结构的相关指标在雌雄个体间无显著差异，提示两性间基因流的不对称性较弱。不过，线粒体基因组呈现出更显著的结构特征，这支持长期存在雄性偏倚的扩散模式。种群动态分析结果与过去种群增长的情况一致，且表明该区域在更新世（Pleistocene）冰期消融后，约于距今1250至12500年前发生了种群扩张事件。本研究结果显示，造访集群栖息位点的蝙蝠间存在较高的基因流，种群连通度较高，该区域的大陆地区可被视为一个统一的大型基因库，用于开展管理与保护工作。