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.

温度会影响从单分子到整个生物的各个级别的生物学。然而，温度对包括蛋白质合成和养分摄取在内的重要细胞过程的影响仍然很少了解。解决这个长期且备受争议的难题对于更好地理解生物如何应对环境温度的长期变化至关重要。在这里，研究人员将针对独立适应高温的极端环境的两组细菌解决这个问题。该方法将将最近开发的理论的扩展与新技术在监测蛋白质合成中的新应用相结合。这项研究将提供一个一般的预测框架，具有改变我们对热生理发展的理解的潜力。研究人员还将通过在K-12和大学级别的指导和宣传来整合研究和教育。研究生将接受培训，将他们的研究与公众传达，从而增加向社区的外展工作。将在不同的场所开发和呈现温度对生物系统的影响的模块，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，代谢和健身之间的联系仍然是进化生理学的基本挑战。关于热力学影响对生理率的相对重要性与生化适应对生物体性能的温度依赖性的相对重要性的辩论尤其引起争议。为了更好地区分可能有助于热性能演变的替代机制，PI提议扩展有关微生物生长速率和基因表达的相互依存的最近开发的理论，以研究温度对蛋白质合成和营养代理之间对代谢速率和细胞分配的影响如何对适应性产生的影响。生长理论模型将确定在不同温度下的生长速率和资源分配之间的关系，用于两个嗜热蓝细菌的生态不同的成员，这些成员沿地热梯度沿地热梯度汇总辐射。此外，使用下一代测序方法对核糖体活性的表征将连接模型所描述的生物级现象与其基因表达的潜在分子机制。实验设计将确定温度影响对生理速率的相对贡献与温度补偿，适应性机制，以促进热性能的演变。它将通过同时考虑到有限的细胞资源对生长施加的生长的限制，从而改善对基因表达，代谢和适应性如何改变生物体的热生态裂市场如何改变基因表达，对基因表达如何改变的预测，从而改善了现有理论的改善。总之，这项研究将提供有关推动利基分化和热专业化的机制的全新观点。这些研究的教育影响还将涉及从博士后水平到K-12的学生的培训和指导，并包括来自代表性不足的人群的学生。该项目由综合生态生理学计划在综合有机体系统的划分中共同提供，并通过实验性启发竞争性的奖项来反映出NSF的启发性宣传。和更广泛的影响审查标准。