Price Dana C, Brennan Julia R, Wagner Nicole E, Egizi Andrea M
Department of Entomology, Center for Vector Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States of America.
Tick-Borne Disease Laboratory, Monmouth County Mosquito Control Division, Tinton Falls, NJ, United States of America.
PeerJ. 2021 Nov 9;9:e12313. doi: 10.7717/peerj.12313. eCollection 2021.
Tick-borne diseases, such as those transmitted by the blacklegged tick , are a significant and growing public health problem in the US. There is mounting evidence that co-occurring non-pathogenic microbes can also impact tick-borne disease transmission. Shotgun metagenome sequencing enables sampling of the complete tick hologenome-the collective genomes of the tick and all of the microbial species contained therein, whether pathogenic, commensal or symbiotic. This approach simultaneously uncovers taxonomic composition and allows the detection of intraspecific genetic variation, making it a useful tool to compare spatial differences across tick populations. We evaluated this approach by comparing hologenome data from two tick samples ( = 6 ticks per location) collected at a relatively fine spatial scale, approximately 23 km apart, within a single US county. Several intriguing variants in the data between the two sites were detected, including polymorphisms in both in the tick's own mitochondrial DNA and that of a rickettsial endosymbiont. The two samples were broadly similar in terms of the microbial species present, including multiple known tick-borne pathogens (, and ), filarial nematodes, and and species. We assembled the complete genome of the rickettsial endosymbiont (most likely ) from both populations. Our results provide further evidence for the use of shotgun metagenome sequencing as a tool to compare tick hologenomes and differentiate tick populations across localized spatial scales.
蜱传疾病，如由黑脚蜱传播的疾病，在美国是一个重大且日益严重的公共卫生问题。越来越多的证据表明，同时存在的非致病微生物也会影响蜱传疾病的传播。鸟枪法宏基因组测序能够对完整的蜱全基因组进行采样，蜱全基因组是蜱及其体内所有微生物物种（无论是致病的、共生的还是共生的）的集体基因组。这种方法同时揭示了分类组成，并允许检测种内遗传变异，使其成为比较蜱种群空间差异的有用工具。我们通过比较在一个美国县内以相对精细的空间尺度（相距约23公里）采集的两个蜱样本（每个地点6只蜱）的全基因组数据来评估这种方法。在两个地点的数据中检测到了几个有趣的变异，包括蜱自身线粒体DNA和立克次氏体共生菌线粒体DNA中的多态性。这两个样本在存在的微生物种类方面大致相似，包括多种已知的蜱传病原体（如 、 和 ）、丝虫线虫以及 和 物种。我们从这两个种群中组装了立克次氏体共生菌（最有可能是 ）的完整基因组。我们的结果为使用鸟枪法宏基因组测序作为比较蜱全基因组和区分局部空间尺度上的蜱种群的工具提供了进一步的证据。
