Host-mediated regulation of dual obligate intracellular symbionts

细菌和动物之间的亲密关系经常进化，并形成了许多特殊动物生活方式的基础。仅以维管植物汁液为食的昆虫依赖于生活在昆虫宿主的特化细胞内并为昆虫提供营养的细菌伴侣。这些关系已经持续了数亿年，但人们对昆虫和细菌相互依赖的机制知之甚少。该项目解决了这些昆虫如何容忍和培养其居民细菌种群的问题。该项目将包括对实验室叶蝉种群的实验，叶蝉具有一些最专门的共生协会。通常叶蝉怀有两种不同的共生体类型，提供宿主所需的互补营养。研究人员将使用新的基因组和分子技术来确定叶蝉物种用来维持共生细菌的机制。为了了解区分细菌类型的特定宿主机制，研究人员将利用具有不同细菌作为共生体的相关叶蝉物种之间的比较。该项目将为德克萨斯大学的众多本科生提供深入的研究经验。这也将是一个博士后研究人员的长期研究计划的基础，该研究人员计划未来在昆虫-细菌关系方面的工作。此外，叶蝉是植物的许多病毒和细菌疾病的主要媒介，包括美国的许多主要农作物。因此，叶蝉是农业系统中最严重的害虫之一。因此，研究人员将在两种臭名昭著的北美害虫物种上进行所有实验。这些结果将为这些害虫物种如何与微生物（包括共生体和病原体）相互作用提供新的见解。

Intimate associations between bacteria and animals have evolved frequently and form the basis for many specialized animal lifestyles. Insects that feed only on sap of vascular plants depend on bacterial partners that live within specialized cells of their insect hosts and that provide nutrients to the insects. These relationships have persisted for hundreds of millions of years, yet little is known about what mechanisms allow both insects and bacteria to rely on each other. This project addresses the question of how these insects tolerate and foster their resident bacterial populations. The project will incorporate experiments on laboratory populations of leafhoppers, which have some of the most specialized symbiotic associations. Typically leafhoppers harbor two different symbiont types that provide complementary sets of nutrients required by the hosts. Investigators will use new genomic and molecular technologies to determine the mechanisms that leafhopper species use to maintain their symbiotic bacteria. To understand the specific host mechanisms that differentiate among bacterial types, investigators will make use of comparisons between related leafhopper species that have different bacteria as symbionts.This project will give in-depth research experiences to numerous undergraduates at the University of Texas. It will also be the basis for the long-term research program of a postdoctoral researcher who plans future work on insect-bacterial relationships. In addition, leafhoppers are primary vectors of many viral and bacterial diseases of plants, including many major agricultural crops in the United States. For this reason, leafhoppers are some of the most severe insect pests of agricultural systems. Thus, investigators will perform all experiments on two notorious North American pest species. These results will provide new insight into how these pest species interact with microorganisms, including both symbionts and disease organisms.