Characterizing Diverse Phage Roles in a Defensive Symbiosis

昆虫和其他动物经常感染母系遗传的共生细菌，这些细菌可以通过提供营养或宿主保护而使其动物宿主受益。许多有益的共生体本身也感染了称为噬菌体的病毒，噬菌体有能力以关键方式影响宿主生物学，但它们在动物-细菌共生中的作用却知之甚少。在豌豆蚜中，细菌共生体防御汉密尔顿氏菌（Hamiltonella defensa）可以保护豌豆免受寄生蜂的攻击，但只有当称为APSE的噬菌体也存在时。除了这种保护作用外，人们对APSE对H的影响知之甚少。防御和蚜虫生物学，特别包括APSE如何有助于寄生虫的死亡和共生体丰度的调节中的潜在作用。该项目将使用包括基因组学和分子生物学在内的多种方法来表征APSE在保护性共生的调节和维持中的作用，并确定导致黄蜂死亡的特定因素。解读噬菌体-共生体相互作用对于研究动物-微生物相互作用以及理解许多重要经济昆虫（如蚜虫）的生物学非常重要。拟议的工作将产生的信息具有实际意义的害虫种群的管理和细菌节肢动物协会，这是广泛存在于自然界中的建立和维护中的作用。这项研究的跨学科性质也非常适合作为培养共生，细胞生物学，寄生虫学和分子过程界面的年轻科学家的平台。该项目将培训高中生、本科生和研究生以及博士后研究人员。

Insects and other animals are frequently infected with maternally inherited symbiotic bacteria, which can benefit their animal hosts by providing nutrition or host protection. Many beneficial symbionts are themselves infected with viruses called bacteriophages, which have the capacity to impact host biology in critical ways, yet their roles in animal-bacterial symbioses are poorly understood. In the pea aphid, Acyrthosiphon pisum, the bacterial symbiont Hamiltonella defensa confers protection from attack by parasitic wasps, but only when bacteriophages called APSEs are also present. Aside from this role in protection, little is known about the influence of APSEs on H. defensa and aphid biology, including specifically how APSEs contribute to the demise of parasites and the potential role in the regulation of symbiont abundance. This project will use a combination of approaches, including genomics and molecular biology, to characterize the roles of APSEs in the regulation and maintenance of the protective symbiosis and to identify specific factors responsible for wasp mortality. Deciphering phage-symbiont interactions is important to the study of animal-microbial interactions generally and to understanding the biology of many economically important insects like aphids. The proposed work will yield information of practical importance for the management of pest insect populations and on the role of phages in the establishment and maintenance of bacterial-arthropod associations, which are widespread in the natural world. The interdisciplinary nature of this research is also well suited as a platform to train young scientists at the interface of symbiosis, cell biology, parasitology, and molecular processes. This project will train high school students, undergraduate and graduate students, and post-doctoral researchers.