The genetic signature of range expansion in a disease vector - the black-legged tick

Monitoring and predicting the spread of emerging infectious diseases requires that we understand the mechanisms of range expansion by its vectors. Here, we examined spatial and temporal variation of genetic structure among 13 populations of the Lyme disease vector, the black-legged tick, in southern Quebec, where this tick species is currently expanding and Lyme disease is emerging. Our objective was to identify the primary mode of tick movement into Canada based on observed spatial and temporal genetic patterns. Upon genotyping ten microsatellite loci from 613 tick specimens, we found multiple genetic signatures of frequent long-distance dispersal events, supporting the hypothesis that migratory birds are the primary carriers of black-legged ticks into southern Quebec. When we compared results from analyses of pairwise differences among ticks collected from eight different sites at different years between 2011 and 2014, we found that genetic variation observed among tick individuals ap...

监测与预测新发传染病的传播，有赖于阐明其媒介生物的种群扩张机制。本研究针对魁北克南部13个莱姆病（Lyme disease）媒介——黑腿蜱（black-legged tick）种群的遗传结构时空变异展开分析——该区域目前正处于该蜱种的扩张阶段，且莱姆病呈新发态势。本研究旨在基于观测到的时空遗传模式，明确黑腿蜱传入加拿大的主要扩散途径。我们对613份黑腿蜱样本的10个微卫星位点（microsatellite loci）进行基因分型后，检测到频繁发生长距离扩散事件的多重遗传信号，这一结果支持了"候鸟是将黑腿蜱携带至魁北克南部的主要载体"这一假说。当我们比对2011至2014年间不同年份采集自8个不同地点的蜱样本的成对差异分析结果时，我们发现蜱个体间观测到的遗传变异...