Data from: Whole genome sequencing reveals clade-specific genetic variation in blacklegged ticks

Ticks and tick-borne pathogens represent the greatest vector-borne disease threat in the US. Blacklegged ticks are responsible for most human cases, yet the disease burden is unevenly distributed across the northern and southern US. Understanding the genetic characteristics influencing phenotypic differences in tick vectors is critical to elucidating disparities in tick-borne pathogen transmission dynamics. Applying evolutionary analyses to molecular variation in natural tick populations across ecological gradients will help identify signatures of local adaptation, which will improve control and mitigation strategies. In this study, we performed whole genome nanopore sequencing of individual (n=1) blacklegged ticks across their geographical range (Minnesota, Pennsylvania, and Texas) to evaluate genetic divergence among populations. Our integrated analyses identified genetic variants associated with numerous biological processes and molecular functions that segregated across populations. Notably, northern populations displayed genetic variants in genes linked to xenobiotic detoxification, transmembrane transport, and sulfation that may underpin key phenotypes influencing tick dispersal, host associations, and vectorial capacity. Nanopore sequencing further allowed the recovery of complete mitochondrial and commensal endosymbiont genomes. Our study provides further evidence of genetic divergence in epidemiologically relevant gene families among blacklegged tick clades. This report emphasizes the need to elucidate the genetic basis driving divergence among conspecific blacklegged tick clades in the US.蜱虫及蜱传病原体是美国最主要的虫媒疾病威胁。黑腿蜱（Blacklegged ticks）是多数人类蜱传疾病病例的传染源，但美国南北地区的疾病负担分布并不均衡。解析调控蜱媒表型差异的遗传特征，对于阐明蜱传病原体传播动态的地域差异至关重要。对不同生态梯度下自然蜱虫种群的分子变异开展进化分析，有助于识别局部适应的遗传印记，进而优化防控与缓解策略。本研究对分布于其地理分布范围（明尼苏达州、宾夕法尼亚州与得克萨斯州）的黑腿蜱个体（n=1）开展全基因组纳米孔（nanopore）测序，以评估种群间的遗传分化。本研究的整合分析鉴定出与众多生物学过程及分子功能相关的遗传变异，这些变异在不同种群间存在分化。值得注意的是，北部种群的基因中存在与异生物质解毒（xenobiotic detoxification）、跨膜运输（transmembrane transport）及硫酸化作用（sulfation）相关的遗传变异，这些变异可能是调控蜱虫扩散、宿主关联及媒介效能（vectorial capacity）的关键表型的分子基础。纳米孔测序还实现了完整线粒体基因组与共生性内共生体（commensal endosymbiont）基因组的组装恢复。本研究进一步证实了黑腿蜱演化支（clade）间与流行病学相关基因家族的遗传分化。本研究强调，亟需解析美国境内同种黑腿蜱不同演化支间遗传分化的分子基础。