Stochastic phenotype switching controlled by c-di-GMP in Vibrio cholerae

微生物可以形成称为生物膜的群落，影响人类活动的许多方面。例如，微生物可用于处理废水和提高农业土壤生产力。了解微生物如何在不同环境中组织和持续存在对于促进有益结果以及减轻有害影响非常重要。 该项目将重点关注微生物在不断变化的环境中生存的惊人能力-通过一个称为表型多样性的过程-使它们能够产生具有广泛行为或特征的后代。 微生物表型多样性行为的预测是一个尚未解决的主要问题。 本计画将利用环境细菌与人类病原体霍乱弧菌，探讨细菌产生表型多样性的机制。 从该项目中学到的基本原理将直接与其他微生物相关，从而促进微生物的管理和工程，以获得有益的结果。此外，该项目将为本科生和研究生，包括代表性不足群体的个人提供研究培训。新的知识将通过与中学科学教育工作者和印象5，在兰辛，MI的科学博物馆的合作，与广大观众分享。该项目将调查的第二信使双-（3-5）-环二聚鸟苷单磷酸（c-di-GMP）在控制霍乱弧菌克隆种群的表型多样性的作用。c-di-GMP通过复杂的信号网络整合环境信号，以控制运动和生物膜生活方式之间的转变等因素。假设是c-di-GMP信号改变了转录调节对分子过程固有的随机波动的敏感性，以控制不同表型的比例。该项目将使用数学建模，定量显微镜和行为跟踪的组合来量化不同实验条件下表型多样性的调节。细胞跟踪和落射荧光显微镜将用于直接在单细胞中将信号传导活性与行为相关联。将使用延时实验定量生长细胞中能动表型和生物膜形成表型之间的转换速率。最后，将使用遗传方法来操纵c-di-GMP水平和转录调节，以测试理论模型的特定预测。总的来说，这个项目将阐明设计原则，允许信号网络整合随机波动与环境信号，以产生和控制克隆种群中有利的表型多样性。

Microbes can form communities called biofilms that affect many aspects of human activities. For example, microbes can be used to treat wastewater and improve agricultural soil productivity. Understanding how microbes organize and persist in different environments is important for promoting beneficial outcomes, as well as mitigating harmful effects. This project will focus on an amazing ability microbes have for surviving in changing environments--through a process called phenotypic diversity--which enables them to produce progeny with a wide range of behaviors or characteristics. Predicting phenotypic diversity behaviors in microbes is a major unsolved problem. This project will use the environmental bacterium and human pathogen, Vibrio cholerae, to investigate the mechanisms used by bacteria to generate phenotypic diversity. The fundamental principles learned from this project will be directly relevant to other microorganisms, thus, facilitating the management and engineering of microbes for beneficial outcomes. In addition, this project will provide research training for undergraduate and graduate students, including individuals from underrepresented groups. New knowledge will be shared with a broad audience through collaborations with secondary science educators and Impression 5, a science museum in Lansing, MI.This project will investigate the role of the second messenger bis-(3-5)-cyclic dimeric guanosine monophosphate (c-di-GMP) in controlling phenotypic diversity in clonal populations of Vibrio cholerae. c-di-GMP integrates environmental signals through a sophisticated signaling network to control, among other factors, the transition between motile and biofilm lifestyles. The hypothesis is that c-di-GMP signaling changes the sensitivity of transcriptional regulation to stochastic fluctuations inherent to molecular processes to control the proportions of different phenotypes. This project will use a combination of mathematical modeling, quantitative microscopy, and behavioral tracking to quantify the regulation of phenotypic diversity under different experimental conditions. Cell tracking and epifluorescence microscopy will be used to correlate signaling activity with behavior directly in single cells. The transition rates between motile and biofilm-forming phenotypes in growing cells will be quantified using time-lapse experiments. Finally, a genetic approach will be used to manipulate c-di-GMP levels and transcription regulation to test specific predictions from theoretical models. Overall, this project will elucidate design principles that allow signaling networks to integrate stochastic fluctuations with environmental signals to generate and control advantageous phenotypic diversity in clonal populations.