Effects of The Rate of Environmental Change on Mutational Patterns and Evolutionary Constraints

环境变化率对突变模式和进化限制的影响

• 批准号: 10664044
• 负责人: Sonia Singhal
• 金额: $ 18.31万
• 依托单位: SAN JOSE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10664044
• 关键词: Address; Affect; Bacteriophages; Biological Models; Biology; Cystovirus; Data; Dependence; Disease; Double-Stranded RNA; Engineering; Environment; Evolution; Exposure to; Frequencies; Future; Generations; Genetic; Genetic Anticipation; Genome; Genotype; Goals; Growth; Haplotypes; Heat-Shock Response; High temperature of physical object; Knowledge; Measures; Modeling; Mutation; Mutation Fixation; Organism; Pathogenicity; Pattern; Phenotype; Play; Population; RNA Viruses; Research; Resistance; Role; Seasons; Shapes; Stress; Temperature; Testing; Theoretical model; Time; Viral; Virus; Work; climate change; environmental change; expectation; experience; experimental study; extracellular; mutant; pleiotropism; predictive modeling; pressure; sample fixation; thermal stress; thermostability; tool; trait

PROJECT SUMMARY Populations must be able to adapt in environmental conditions that may change either suddenly (within one generation) or gradually (over multiple generations). Theoretical models predict that these differences in the rate of environmental change will fundamentally influence the number and effect sizes of mutations that fix, but few studies have mechanistically examined the genetics of adaptation in environments that become more stressful over time. Moreover, the theoretical models do not always account for well-known phenomena that introduce evolutionary constraints, such as genotype by environment (GxE) interactions and pleiotropy. The goal of this research is to compare patterns of genome evolution and effects of mutations in RNA viruses under sudden or gradual environmental change, and to use these data to evaluate theoretical models of adaptation in environments that change at different rates. The project uses temperature-resistant populations of the model bacteriophage ɸ6 Cystovirus that were previously generated through an evolution experiment in which viral populations were exposed to a heat shock temperature that was increased either gradually (Gradual populations) or suddenly (Sudden populations). Here, we propose to use these populations to examine patterns of mutation fixation and to characterize the role of GxE interactions and pleiotropy in environments that change at different rates. Specifically, we will 1) evaluate the number of mutations, their times to fixation, and haplotype diversity of Sudden and Gradual populations; and 2) measure the effects of sequential mutations from select lineages on both viral thermostability and growth rate, and correlate those effects with the rate of environmental change experienced by the lineage. Our study will address the central question in evolutionary biology of how changes to the strength and tempo of selection influence adaptation, and will illuminate the mechanistic underpinnings of adaptation in different rates of environmental change. Establishing the selective pressures and constraints at play in changing environments will give us tools to predict or control viral evolution.

项目概要 种群必须能够适应可能突然变化的环境条件 （一代人之内）或逐渐地（多代人）预测。 这些环境变化速度的差异将从根本上影响数量 以及修复突变的效应大小，但很少有研究从机制上检查遗传学 此外，随着时间的推移，适应压力变得更大的环境。 模型并不总是解释引入进化约束的众所周知的现象， 例如环境基因型（GxE）相互作用和多效性。 比较突如其来的情况下 RNA 病毒的基因组进化模式和突变的影响 或逐渐的环境变化，并使用这些数据来评估理论模型 适应以不同速率变化的环境。该项目使用耐温材料。 模型噬菌体 ɸ6 囊病毒的种群，之前通过 进化实验，其中病毒群体暴露于热休克温度 逐渐增加（逐渐增加的人口）或突然增加（突然增加的人口）。 我们建议使用这些群体来检查突变固定的模式并表征 GxE 相互作用和多效性在以不同速率变化的环境中的作用。 具体来说，我们将 1) 评估突变的数量、固定时间和单倍型 突然和渐进种群的多样性；2) 测量连续突变的影响 从选定的谱系中分析病毒热稳定性和生长速率，并将这些影响与 我们的研究将针对中心的环境变化率。 进化生物学中关于选择强度和节奏的变化如何影响的问题 适应，并将阐明不同速率下适应的机制基础 确定环境变化中起作用的选择性压力和约束。 环境将为我们提供预测或控制病毒进化的工具。