Applying bacterial growth theory to understand the evolution of thermal performance

应用细菌生长理论来了解热性能的演变

• 批准号: 1755407
• 负责人: Scott Miller
• 金额: $ 58.08万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1755407&HistoricalAwards=false
• 关键词: Applying; bacterial; growth; theory; understand

Temperature affects biology at all levels, from single molecules to whole organisms. However, the effects of temperature on important cellular processes including protein synthesis and nutrient uptake remain poorly understood. Resolution of this longstanding and hotly debated puzzle is essential for developing a better understanding of how organisms respond to long-term changes in environmental temperature. Here, the investigators will address this issue for two groups of bacteria from extreme environments that have independently adapted to high temperatures. The approach will combine the extension of recently developed theory with the novel application of new technologies for monitoring protein synthesis. This research will provide a general predictive framework with the potential to transform our understanding of the evolution of thermal physiology. The investigators will also integrate research and education through mentoring and outreach at both K-12 and university levels. Graduate students will be trained to communicate their research to the general public, increasing the outreach efforts to the community. Modules on effect of temperature on biological systems will be developed and presented at different venues to reach a broad spectrum of K-12 students. Finally, underrepresented students will be involved in all aspects of this research.Understanding the links between temperature, metabolism and fitness remains a fundamental challenge in evolutionary physiology. The longstanding debate over the relative importance of thermodynamic effects on physiological rates versus biochemical adaptation for the temperature dependence of organism performance has been particularly contentious. To better distinguish among alternative mechanisms that may contribute to the evolution of thermal performance, the PI proposes to extend recently developed theory on the interdependence of microbial growth rate and gene expression to investigate how temperature effects on fitness arise from both thermodynamic effects on metabolic rates and cell allocation trade-offs between protein synthesis and nutrient metabolism. Growth theory models will determine the relationship between growth rate and resource allocation at different temperatures for ecologically divergent members of two clades of thermophilic cyanobacteria that have convergently radiated along geothermal gradients. Further, characterization of ribosome activity with a next-generation sequencing approach will connect the organism-level phenomena described by the models with their underlying molecular mechanisms of gene expression. The experimental design will enable the determination of the relative contributions of temperature effects on physiological rates versus temperature-compensating, adaptive mechanisms for the evolution of thermal performance. It will improve on existing theory by simultaneously accounting for both the temperature effects on metabolic rates and the constraints imposed on growth by finite cellular resources, thereby enabling improved predictions for how gene expression, metabolism and fitness change along an organism's thermal niche. Together, the research will provide a fresh perspective on the mechanisms that drive niche differentiation and thermal specialization. The educational impacts of these research will also involve training and mentoring of students from the postdoctoral level to K-12 and include students from underrepresented populations.This project is co-funded by the Integrative Ecological Physiology Program in the Division of Integrative Organismal Systems and by the Experimental Program to Stimulate Competitive Research.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.

温度影响着从单个分子到整个生物体的各个层面的生物学。然而，温度对包括蛋白质合成和营养吸收在内的重要细胞过程的影响仍然知之甚少。解决这个长期争论不休的难题对于更好地理解生物如何对环境温度的长期变化做出反应至关重要。在这里，研究人员将为来自极端环境的两组细菌解决这个问题，这两组细菌已经独立适应了高温。该方法将结合最近发展的理论的扩展与监测蛋白质合成的新技术的新应用。这项研究将提供一个通用的预测框架，有可能改变我们对热生理进化的理解。调查人员还将通过K-12和大学水平的指导和外展，将研究和教育结合起来。研究生将接受培训，与公众交流他们的研究，增加对社区的推广工作。关于温度对生物系统影响的模块将被开发并在不同的场地展示，以达到广泛的K-12学生。最后，代表性不足的学生将参与这项研究的各个方面。理解温度、新陈代谢和健康之间的联系仍然是进化生理学的一个基本挑战。长期以来，关于热力学效应对生理速率的相对重要性与生物化学适应对生物体性能温度依赖性的相对重要性的争论一直特别有争议。为了更好地区分可能有助于热性能进化的其他机制，PI建议扩展最近发展的关于微生物生长速度和基因表达相互依赖的理论，以研究温度对适应性的影响是如何从热力学对代谢率的影响和蛋白质合成和营养代谢之间的细胞分配权衡中产生的。生长理论模型将确定沿地热梯度辐合辐射的两个嗜热蓝藻分支的生态分化成员在不同温度下的生长速率和资源分配之间的关系。此外，利用下一代测序方法表征核糖体活性将把模型所描述的生物水平现象与其潜在的基因表达分子机制联系起来。实验设计将能够确定温度对生理速率的影响与温度补偿的相对贡献，热性能进化的自适应机制。它将通过同时考虑温度对代谢率的影响和有限细胞资源对生长的限制来改进现有的理论，从而改进对基因表达、代谢和适应性如何沿着生物体的热生态位变化的预测。总之，这项研究将为驱动生态位分化和热专业化的机制提供一个新的视角。这些研究的教育影响还将涉及从博士后到K-12年级的学生的培训和指导，并包括来自代表性不足人群的学生。本项目由综合生物系统部门的综合生态生理学项目和刺激竞争性研究的实验项目共同资助。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。