Integrating population genomics and microbial metagenomics of the lone star tick, an expanding arthropod disease vector

整合种群基因组学和微生物元基因组学的孤星蜱，一种扩大的 节肢动物病媒 项目摘要/摘要 在美国，扁虱是最重要的致病病原体传播媒介。孤零零的星星滴答作响， 美洲钝单胞菌(Amblyomma Americanum)是多种病原微生物的合格媒介。有几个 我们对节肢动物疾病孤星蚤基本生物学的理解中的关键知识差距 正在迅速将其地理分布扩展到中西部和东北部的媒介。人们对此知之甚少 扁虱基因组的多样性和扁虱微生物群的微生物多样性如何影响 用来感染扁虱的特定病原体。这项研究的主要目标是产生一个完整的基因 壁虱传播疾病的流行病学，结合了媒介的基因组多样性，物种多样性 它的微生物群，以及已知病原体的流行情况。最重要的假设是基因组多样性 与微生物物种多样性呈正相关，与病原菌呈负相关 流行率。首席调查员将使用下一代DNA测序来测试最重要的 提出假设，并通过三个具体目标实现本项目的主要目标：(1)调查空间 西部和北部物种范围附近孤星硬蜱种群间基因组变异的分布 边界。可行的假说是，基因组多样性的克隆对应于日益紧张的压力 物种范围边缘的气候条件，表明范围的扩大与 微进化的变化。(2)孤星硬蜱微生物群的特征及其与寄主的关系 基因组多样性。工作假说是壁虱基因组多样性越大，微生物数量就越多。 物种多样性，表明寄主基因型影响微生物群的组成。(三)检视效果 基因组多样性和微生物多样性对个体硬蜱病原体感染的影响。工作假说是 个体扁虱基因组和微生物的高度多样性减少了病原体的感染，这表明 壁虱体内微生物的竞争性相互作用控制着特定的壁虱传播病原体的流行 在更大的范围内。这项研究具有创新性，因为它将(A)在人口研究方法上独树一帜 基因组学、细菌元基因组学和媒介病原体的群落生态学；(B)产生基因组 这些数据将成为今后美洲按蚊和其他扁虱研究的宝贵资源；以及(C)说明 在实验室饲养的硬蜱中考虑基因组和微生物组多样性的重要性 病原体传播、宿主免疫学和杀螨剂。这项研究具有重要意义，因为它将揭示 可能影响病原体动态的个体扁虱内的微生物相互作用。发现细菌 竞争性地抑制体内病原体感染的谱系或集合体将是 控制由扁虱和其他节肢动物传播的疾病。此外，这项拟议的研究将加强 为佩珀丁大学的研究提供基础设施，并将为本科生提供关键的机会 对生物医学科学和媒介生物学的职业感兴趣的学生。

Integrating population genomics and microbial metagenomics of the lone star tick, an expanding arthropod disease vector PROJECT SUMMARY/ABSTRACT Ticks are the most important vectors of disease-causing pathogens in the United States. The lone star tick, Amblyomma americanum, is a competent vector of various pathogenic microorganisms. There are several critical knowledge gaps in our understanding of the basic biology of the lone star tick, an arthropod disease vector that is rapidly expanding its geographic distribution into the Midwest and Northeast. Little is known about how the diversity of the tick’s genome and the microbial diversity of the tick’s microbiome affect the ability of specific pathogens to infect a tick. The main objective of this research is to generate an integrated genetic epidemiology for tick-borne diseases that incorporates the genomic diversity of vector, the species diversity of its microbiome, and the prevalence of known pathogens. The overarching hypothesis is that genomic diversity of tick vectors is positively associated with microbial species diversity and negatively associated with pathogen prevalence. The Principal Investigator will use next-generation DNA sequencing to test the overarching hypothesis and achieve the main objective of this project through three specific aims: (1) Investigate the spatial distribution of genomic variation among populations of lone star tick near the western and northern species range boundaries. The working hypothesis is that a cline of genomic diversity corresponds to increasingly stressful climatic conditions at the edges of the species range, suggesting that range expansion coincides with microevolutionary change. (2) Characterize the microbiome of lone star tick and assess its relationship to host genomic diversity. The working hypothesis is that greater genomic diversity of ticks permits a greater microbial species diversity in ticks, suggesting that host genotype affects microbiome composition. (3) Examine the effects of genomic diversity and microbial diversity on pathogen infection in individual ticks. The working hypothesis is that high genomic and microbial diversity of individual ticks reduces infection by pathogenic bacteria, suggesting that competitive interactions of microbes inside of ticks govern the prevalence of specific tick-borne pathogens at broader scales. This study is innovative because it will (a) uniquely bridge methodologies in population genomics, bacterial metagenomics, and community ecology of vector-borne pathogens; (b) generate genomic data that will be a valuable resource for future investigations of A. americanum and other ticks; and (c) illuminate the importance of accounting for genomic and microbiome diversity in laboratory-reared ticks used in studies of pathogen transmission, host immunology, and acaricides. This study is significant because it will shed light on the microbial interactions within individual ticks that may influence pathogen dynamics. Discovering bacterial lineages or assemblages that competitively inhibit infection by pathogens within ticks will be a significant step in controlling diseases vectored by ticks and other arthropods. Furthermore, this proposed study will enhance the infrastructure for research at Pepperdine University and will provide crucial opportunities to undergraduate students interested in careers in biomedical sciences and vector biology.