Sensing more than a quorum: The role of pheromones in the light-organ symbiont Vibrio fischeri

植物和动物一直被细菌定殖，这些共生微生物通常有助于其宿主的有益过程和/或疾病。许多共生细菌使用信息素信号进行通信，使它们能够在感染期间协调群体行为。这种信息素信号通常被称为？群体感应？because high高cell细胞density密度isnecessary必要for pheromones信息素to build建立up.然而，a？法定人数？通常不足以完全诱导信息素介导的行为，细菌信息素也不是简单的普查信号。重要的是，信息素也可以在细菌之间传递宿主环境的各个方面。该项目将使用遗传学，分子，显微镜和微生物学的方法，在利用细菌弧菌和它的天然宿主鱿鱼Euprymna sputteropes之间的易处理的共生模型，以研究宿主和共生体的条件之间的关系？信息素的用途。费歇尔弧菌中发现了信息素信号，并且它仍然是此类研究中最好理解的模型系统之一。这种共生感染发生在只被费氏弧菌定殖的透明组织中，并且感染期间的信息素信号导致细菌发射生物发光，使得感染相对简单并且调节输出易于监测。该项目的科学目标是确定宿主环境的哪些方面导致细菌生物发光的诱导，并确定信息素在宿主的通信条件中发挥什么作用。第三个目标是将细菌-宿主共生的研究整合到本科教育中，既可以通过直接再现研究，也可以通过生成材料来促进科学论文的课堂讨论。该项目将深入了解环境共生细菌在宿主中的遭遇，以及它们对宿主的感知如何与它们对信息素的使用相结合。该项目还将帮助培养年轻科学家。

Plants and animals are consistently colonized by bacteria, and thesesymbiotic microorganisms often contribute to beneficial processes and/or diseasein their hosts. Many symbiotic bacteria communicate using pheromone signals,allowing them to coordinate group behaviors during infection. Such pheromonesignaling is typically called ?quorum sensing?, because high cell density isnecessary for pheromones to build up. However, a ?quorum? is typically notsufficient to induce pheromone-mediated behaviors fully, and bacterialpheromones are not simply census-taking signals. Importantly, the pheromonesmay also function to communicate aspects of the host environment among thebacteria. This project will use genetic, molecular, microscopic, and microbiologicalapproaches in exploiting the tractable model symbiosis between thebacterium Vibrio fischeri and its natural host squid Euprymna scolopes toexamine the relationship between conditions in the host and the symbiont?s useof pheromones. Pheromone signaling was discovered in V. fischeri and itremains among the best-understood model systems for such study. Thesymbiotic infection occurs in transparent tissue that is only colonized by V.fischeri, and pheromone signaling during infection results in the emission ofbioluminescence by the bacteria, making the infection relatively simple and theregulatory output easy to monitor. The scientific aims of this project are todetermine what aspects of the host environment lead to the induction of bacterialbioluminescence and to determine what role pheromones play in communicatingconditions in the host. A third aim is to integrate research on bacteria-hostsymbioses into undergraduate education, both through direct emersion inresearch and through the generation of materials to facilitate in-class discussionof scientific papers. The project will provide insight into the environmentsymbiotic bacteria encounter in a host, and how their perception of the hostenvironment can be integrated with their use of pheromones. The project willalso help train young scientists.