NSF Postdoctoral Fellowship in Biology FY 2021: Evolution of bacterial strategies for evading predation by amoebae

该行动资助了2021财年的NSF生物学博士后研究奖学金，即调查基因组，环境和表型之间相互作用的生命规则的综合研究。该研究金支持研究员的研究和培训，以创新的方式为生活规则领域做出贡献。变形虫（称为Dictyosteelium discoideum）是一种单细胞原生生物，生活在土壤中，吃细菌，有时也作为一些细菌的宿主。虽然D.尽管discoideum几十年来一直作为实验室模型，但关于它与野生细菌的相互作用如何影响细菌进化的知之甚少。到目前为止，很少有基因和分子相互作用，使细菌逃脱捕食者或感染和利用他们的潜在捕食者已经确定。本研究的目的是探讨细菌与D. discoideum和测试的假设，远亲细菌已经制定了类似的战略。这将提供深入了解捕食在驱动复杂细菌性状进化中的作用，例如逃避捕食或操纵宿主行为的能力。除了实验工作，该项目将通过让本科生参与研究来增加公众对科学的参与，并将激发旨在向公众传达科学发现过程的游戏和活动。discoideum和20种不同的细菌。阿米巴-细菌相互作用对两个参与者的适应性的影响将被量化，以将细菌分类为有益的猎物、有害的病原体或抵抗捕食但无害的共生体。将使用转录组学来评估D.盘状突，以确定是否在同一类别中的远亲细菌通过靶向相同的宿主途径实现类似的结果。此外，D. discoideum摄取不同的细菌，并且摄取后细菌存活的持续时间将通过显微镜测量。基因表达将被测量和操纵，以确定细菌是否通过刺激D。盘状突过度产生盘状蛋白，盘状蛋白与细胞膜结合并增加细菌在吞噬作用后的存活。最后，比较基因组学将用于寻找有助于逃避捕食的细菌基因。本研究的发现将有助于弥合目前对D.该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. The amoeba (called Dictyostelium discoideum) is a single-celled protist that lives in the soil, eats bacteria, and sometimes serves as a host to some bacteria. Though D. discoideum has served as a laboratory model for decades, relatively little is known about how its interactions with bacteria in the wild affect bacterial evolution. To date, few of the genes and molecular interactions that allow bacteria to escape predators or infect and exploit their would-be predator have been identified. The objective of this study is to explore the mechanisms bacteria use to interact with D. discoideum and test the hypothesis that distantly related bacteria have developed similar strategies. This will provide insight into the role of predation in driving the evolution of complex bacterial traits, such as the ability to evade predation, or manipulate host behavior. In addition to experimental work, this project will increase public participation in science by engaging undergraduate students in research and will inspire games and activities aimed at communicating the process of scientific discovery to the general public.This research investigates interactions between D. discoideum and 20 different bacteria. Effects of amoeba-bacteria interactions on the fitness of both participants will be quantified to categorize bacteria as beneficial prey, harmful pathogens, or predation-resistant but non-harmful symbionts. Transcriptomics will be used to evaluate the response of D. discoideum to each bacterium to determine whether distantly related bacteria in the same category achieve similar outcomes by targeting the same host pathways. Additionally, the rate at which D. discoideum ingests different bacteria and the duration of bacterial survival after ingestion will be measured through microscopy. Gene expression will be measured and manipulated to determine whether bacteria overcome host defenses by stimulating D. discoideum to overproduce the protein discoidin, which binds to cell membranes and increases bacterial survival after phagocytosis. Finally, comparative genomics will be used to look for bacterial genes that contribute to escape from predation. Findings from this study will help to bridge the gap between the present understanding of D. discoideum as a laboratory model and its role in natural microbial ecosystems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.