DISSERTATION RESEARCH: Evolution of Generalism and Specialism in the RNA phage Phi6

论文研究：RNA 噬菌体 Phi6 的通用性和专业性的进化

• 批准号: 0408000
• 负责人: Paul Turner
• 金额: $ 1.2万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0408000&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Evolution; Generalism; Specialism

Biologists have long puzzled why most organisms specialize on few resources, rather than generalize by broadly exploiting the wide variety of resources that nature offers. Generalism seems a more tempting strategy, because it allows a larger niche space and the ability for organisms to thrive across a vast range of habitats. However, specialists appear to predominate in nature, perhaps due to their greater efficiency at exploiting a lesser number of resources. The costs of generalism (and their underlying mechanisms) have proven difficult to study. This research will use mutants of the RNA virus phi-6 that show an expanded ability to infect new host bacteria (i.e., generalist viruses), to examine hypothesized costs of generalism. The mutants will be evolved for hundreds of generations on a single novel host in order to test whether adaptation to the new host necessitates specialization (narrowing of the virus niche). Also, genomes of the evolved viruses will be sequenced to test two competing theories on how mechanisms for specialization evolve at the molecular level. This study is powerful because it uses a harmless virus of bacteria to study general questions regarding host shifts by viruses onto hosts. Virus phi-6 is an especially informative model for studying evolution of segmented RNA viruses, such as Hantavirus and Influenza which infect humans. Thus, results of the study should further the understanding of host-shifts involving pathogenic RNA viruses of higher organisms.

长期以来，生物学家一直困惑为什么大多数生物体只专注于少数资源，而不是通过广泛利用大自然提供的各种资源来进行概括。 普遍主义似乎是一种更具吸引力的策略，因为它允许更大的利基空间以及生物体在广泛的栖息地中繁衍生息的能力。 然而，专家似乎在自然界中占主导地位，这可能是因为他们在开发较少数量的资源时效率更高。 事实证明，普遍主义的成本（及其潜在机制）很难研究。 这项研究将使用 RNA 病毒 phi-6 的突变体，该突变体显示出感染新宿主细菌（即通才病毒）的能力增强，以检验假设的通才成本。 突变体将在单一新宿主上进化数百代，以测试适应新宿主是否需要专门化（缩小病毒生态位）。 此外，还将对进化病毒的基因组进行测序，以测试关于专业化机制如何在分子水平上进化的两种相互竞争的理论。 这项研究之所以强大，是因为它使用无害的细菌病毒来研究有关病毒向宿主转移宿主的一般问题。 病毒 phi-6 是研究分段 RNA 病毒（例如感染人类的​​汉坦病毒和流感病毒）进化的信息丰富的模型。 因此，该研究结果应进一步了解涉及高等生物体致病性 RNA 病毒的宿主转移。