Elucidating Dynamics and Heterogeneity in the Yeast Stress Response

该项目的目标是了解微生物群体中的一些细胞如何能够在环境压力下生存，而同一环境中的其他相同细胞则不能。这种现象被称为“文化异质性”。该项目的目标是研究在酵母细胞培养中存在多少应激反应和存活的变化，然后了解引起这种变化的调节机制。利用酵母作为自由生活微生物的模型，该项目将使用单细胞显微镜来研究单个细胞。了解应激反应和生存中细胞间变异的来源和模式将有助于社会了解如何控制微生物培养，这对人类健康，农业和环境修复都有好处。除了这项研究之外，该项目还将开发一个名为“问科学家”的推广计划，旨在将威斯康星州麦迪逊地区的K-6小学教室与专业和学生科学家联系起来，他们将成为该班的科学笔友。该项目的目标是为教师提供一种机制，使青年学生更多地接触科学和专业科学家。这个项目将结合联合收割机过去的进展，在网络推理与单细胞的调查，了解动态和异质性的酵母酿酒酵母应激反应。过去的工作推断了一个系统水平的信号网络，控制酵母转录组对盐胁迫的反应。该网络已被证明是强大的，但不能捕获信号动力学或细胞间信号变化，这两者在微生物应激防御中都很重要。该项目将通过单细胞分析测试网络预测，旨在通过以下方式捕获信号动力学和文化异质性：1）在盐处理之前和之后在活细胞中进行单细胞显微镜检查，以确定酵母应激反应的荧光标记的调节剂对的定位动力学，以表征调节剂定位模式中的相关性，和2）跟踪表达荧光标记形式的负责转录因子的单个活细胞中代表性转录物的动态变化。结果将涉及动态的转录因子定位的动态目标mRNA和单细胞中的细胞应激耐受的动态。总之，这项研究的结果将增加对文化异质性的模式和机制的理解，这反过来将阐明上游细胞信号网络的变异来源。

The goal of this project is to understand how some cells in a microbial population can survive environmental stress whereas other identical cells in the same environment cannot. This phenomenon is referred to as 'culture heterogeneity'. The goals of the project are to examine how much variation in stress response and survival exists in a culture of yeast cells, and to then understand the regulatory mechanisms that give rise to that variation. Using yeast as a model for free-living microbes, the project will use single-cell microscopy to study individual cells. Understanding both the sources and patterns of cell-to-cell variation in stress responses and survival will help society to understand how to control microbial cultures, which has benefits to human health, agriculture, and environmental remediation. In addition to this research, the project will develop an outreach program called 'Ask a Scientist', which aims to link K-6 elementary classrooms in the Madison, WI area with professional and student scientists who will serve as a science pen-pal for the class. The goal of the project is to provide teachers with a mechanism to increase young students' exposure to science and professional scientists. This project will combine past advances in network inference with single-cell investigations to understand the dynamics and heterogeneity in the yeast Saccharomyces cerevisiae stress response. Past work inferred a systems-level signaling network that controls the yeast transcriptomic response to salt stress. The network has proven powerful, but does not capture signaling dynamics or cell-to-cell signaling variation, both of which are important in microbial stress defense. This project will test network predictions through single-cell analyses designed to capture signaling dynamics and culture heterogeneity by: 1) performing single-cell microscopy in living cells before and after salt treatment to determine the localization dynamics of pairs of fluorescently tagged regulators of the yeast stress response to characterize the correlations in regulator localization patterns, and 2) follow dynamic changes in representative transcripts in single living cells that express a fluorescently tagged version of the responsible transcription factor. Results will relate the dynamics of transcription-factor localization to dynamics of target mRNAs and to the dynamics of cellular stress tolerance in single cells. Together, results of this research will increase understanding of the mode and mechanism of culture heterogeneity, which will in turn illuminate sources of variation in the upstream cellular signaling network.