DISSERTATION RESEARCH: Characteristics of viral host niche evolution

论文研究：病毒宿主生态位进化的特征

• 批准号: 0709823
• 负责人: Christina Burch
• 金额: $ 0.97万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-15 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0709823&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Characteristics; viral; host

While organisms can sometimes expand the range of environments they live in, the genetic and ecological conditions which facilitate expansion are unclear. Proposed here are two experiments which will investigate these conditions using a virus and its bacterial host, Pseudomonas syringae. Both experiments will expose the virus to new hosts, and determine two critical determinants of the likelihood that viral populations will evolve to use the new host: 1) the number of mutations that adapt the virus to these hosts, and 2) the costs these mutations have on the virus' normal host. In the first experiment, host range mutants will be isolated on a number of new hosts to determine if the similarity between the new hosts and the normal host influences the likelihood of host range expansion. In the second experiment, mutations that allow growth on a new host will be compared to mutations that further adapt the virus to this new host. This comparison will enable the investigators to determine if these two ecological scenarios differ in their likelihood of environmental range expansion. Understanding the conditions that facilitate the expansion of an organism's environmental range has long been a fundamental question in ecology and evolutionary biology, and also has importance for addressing applied questions such as the emergence of disease in new host populations (as when SARS emerged in human populations). While theoretical studies have provided an intuitive framework to address this issue, there has been relatively little empirical work investigating factors that influence the likelihood of range expansion. This study seeks to examine some of the ecological and genetic factors that are predicted to influence the likelihood of environmental range expansion.

虽然有机体有时可以扩大它们生活的环境范围，但促进扩张的遗传和生态条件尚不清楚。 这里提出了两个实验，将研究这些条件下使用病毒和它的细菌宿主，假单胞菌。 这两个实验都将使病毒暴露于新的宿主，并确定病毒种群进化以使用新宿主的可能性的两个关键决定因素：1）使病毒适应这些宿主的突变数量，以及2）这些突变对病毒正常宿主的成本。 在第一个实验中，将在许多新宿主上分离宿主范围突变体，以确定新宿主与正常宿主之间的相似性是否影响宿主范围扩展的可能性。 在第二个实验中，允许在新宿主上生长的突变将与使病毒进一步适应该新宿主的突变进行比较。 这种比较将使研究人员能够确定这两种生态情景在环境范围扩展的可能性方面是否不同。 了解促进生物体环境范围扩展的条件长期以来一直是生态学和进化生物学的基本问题，并且对于解决应用问题也很重要，例如新宿主群体中疾病的出现（如SARS在人类中出现）。 虽然理论研究提供了一个直观的框架来解决这一问题，有相对较少的实证工作调查的因素，影响范围扩大的可能性。 这项研究旨在研究一些生态和遗传因素，预测影响环境范围扩大的可能性。