CAREER: Genetic dissection of stress signaling and defense in yeast

该项目的目标是了解具有相似基因组成的个体生物如何对环境压力做出不同的反应。这项研究将重点研究用于食品和饮料工业发酵的啤酒酵母。虽然啤酒酵母可以在许多自然环境中找到，但并不是所有的酵母细胞都能很好地适应与发酵或酿造相关的高乙醇环境。确定导致酵母中乙醇耐受性变异的基因差异有望有两个广泛的科学成果。研究结果可能有助于鉴定出具有更好的农业和生物技术应用能力的酵母。此外，研究结果可以帮助我们了解基因如何控制更复杂生物体（如人类）的应激反应。该项目将通过为阿肯色州的研究生和本科生，包括未被充分代表的少数群体提供科学培训机会，对教育产生影响。此外，通过与当地一家发酵企业的合作，项目团队将开发两门关于酿造科学的本科实验课程，提供发酵微生物学和生物技术方面的实践经验。本研究的长期目标是利用真核生物酿酒酵母模型，了解基因表达的变化如何影响与应激防御相关的表型差异。该策略是利用酵母乙醇反应中广泛的自然变异来研究获得性抗逆性，在这种情况下，经过亚致死压力预处理的细胞获得了在其他致死压力下存活的能力。为了全面鉴定野生酵母菌株具有高获得性抗逆性所需的一系列基因和过程，将生产大量使用CRISPR技术敲除单个基因的品系。然后，通过本体分离分析结合深度测序建立基因型与表型的关系。CRISPR敲除细胞系还将用于鉴定不同酵母菌株中乙醇反应信号网络的关键差异。该研究结果有望为以下方面提供新的见解：1)获得性抗逆性和交叉保护的遗传决定因素；2)这些因素与调节内在抗逆性的因素有何不同；3)负责应激防御自然变异的关键调控因子是否通过基因表达、蛋白质编码潜能或两者的变化来运作；4)压力信号网络在不同基因个体之间的差异。该奖项反映了美国国家科学基金会的法定使命，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。

The goal of this project is to understand how individual organisms with similar genetic makeup can respond differently to environmental stress. The research will focus on studying brewer’s yeast, which is used for industrial fermentation of foods and beverages. Whereas brewer’s yeast can be found in many natural settings, not all yeast cells are well-adapted to tolerate the high-ethanol environments associated with fermentation or brewing. Identifying the gene differences that lead to variation in ethanol tolerance in yeast is expected to have two broad scientific outcomes. The results may permit identification of yeast with better capabilities for agricultural and biotechnology applications. Also, the results could help us understand how genes control stress responses in more complex organisms, such as humans. The project will have educational impacts by providing scientific training opportunities for graduate and undergraduate students in Arkansas, including underrepresented minority groups. In addition, through a partnership with a local fermentation business, the project team will develop two undergraduate laboratory courses on the Science of Brewing, providing hands-on experience in fermentation microbiology and biotechnology. The long-term goal of this research is to understand how variation in gene expression shapes phenotypic differences related to stress defense, using the model eukaryote Saccharomyces cerevisiae. The strategy is to leverage extensive natural variation in the yeast ethanol response in order to investigate acquired stress resistance, where cells pretreated with sub-lethal stress gain the ability to survive an otherwise lethal exposure to stress. To comprehensively identify the suite of genes and processes necessary for high acquired stress resistance in wild yeast strains, a large collection of lines with individual genes knocked out using CRISPR technology will be produced. Then, genotype-to-phenotype relationships will be established by bulk segregant analysis combined with deep sequencing. The CRISPR knock-out lines will also be used to identify key differences in the ethanol-responsive signaling network across diverse yeast strains. The outcomes are expected to provide new insights into: 1) the genetic determinants of acquired stress resistance and cross protection; 2) how these factors differ from those regulating intrinsic stress resistance; 3) whether key regulators responsible for natural variation in stress defense operate through changes in gene expression, protein coding potential, or both; and 4) how stress signaling networks differ across genetically distinct individuals.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.