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.

温度在各个层面影响生物，从单个分子到整个生物体。然而，温度对重要的细胞过程，包括蛋白质合成和营养吸收的影响仍然知之甚少。解决这个长期存在且激烈争论的难题对于更好地理解生物体如何对环境温度的长期变化做出反应至关重要。在这里，研究人员将针对两组来自极端环境的细菌解决这个问题，这些细菌已经独立适应了高温。该方法将联合收割机的扩展最近开发的理论与新的应用新技术监测蛋白质合成。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学演变的理解。调查人员还将通过在K-12和大学层面的指导和推广来整合研究和教育。研究生将接受培训，向公众宣传他们的研究，增加对社区的宣传工作。温度对生物系统的影响模块将在不同的地点开发和介绍，以达到广泛的K-12学生。最后，代表性不足的学生将参与本研究的各个方面。了解温度，新陈代谢和健身之间的联系仍然是进化生理学的一个基本挑战。长期以来，关于热力学对生理速率的影响与生物体性能的温度依赖性的生物化学适应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演变的替代机制，PI建议扩展最近开发的关于微生物生长速率和基因表达相互依赖的理论，以研究温度对健身的影响如何从对代谢速率的热力学影响和蛋白质合成与营养代谢之间的细胞分配权衡中产生。生长理论模型将确定生长速率和资源分配之间的关系，在不同的温度下的生态分歧成员的两个分支的嗜热蓝藻，收敛辐射沿着地热梯度。此外，使用下一代测序方法对核糖体活性进行表征将把模型描述的生物体水平现象与其基因表达的潜在分子机制联系起来。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，热性能演变的自适应机制。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理论，从而能够改进对基因表达、代谢和适应性如何沿着生物体的热生态位沿着变化的预测。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的学生的培训和指导，包括来自代表性不足人口的学生。该奖项由综合有机系统部的综合生态生理学计划和刺激竞争性研究的实验计划资助。该奖项反映了NSF的法定使命，并被认为值得通过以下方式获得支持：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。