RUI: Biology-Physics Collaboration to Investigate the Genetic and Structural Basis of Competence in Bacteria

RUI：生物-物理合作研究细菌能力的遗传和结构基础

• 批准号: 1330511
• 负责人: C. Phoebe Lostroh
• 金额: $ 50.77万
• 依托单位: Colorado College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-15 至 2019-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1330511&HistoricalAwards=false
• 关键词: RUI; Biology; Physics; Collaboration; Investigate

Intellectual Merit: Bacteria have a covering membrane, analogous to human skin, designed to keep their internal components in and foreign bodies out. Some bacteria have developed the ability to import foreign DNA across this membrane and incorporate it into their own genomes. This ability is called natural transformation or competence. Because competent bacteria can import everything from their own native DNA to animal DNA, they can adapt rapidly in stressful environments, such as in the presence of antibiotics. This research project is to better understand how bacteria are able to find DNA and move it across their membranes. What is currently known is that some bacteria can make structures, called Type IV Pili, which consist of pores through their membranes and through which associated long appendages can project outward. Type IV Pili are used by bacteria to pull themselves across a surface, essentially using the appendages as retractable grappling hooks. The machinery responsible for competence is believed to be similar in structure to Type IV Pili. This similarity suggests two hypotheses: first, the set of genes that build the competence machine must be similar to the set of genes that build Type IV Pili, and second, the competence machine performs similar actions to Type IV Pili, albeit for a different purpose. This research will use Type IV Pili genes to identify potential competence genes and then evaluate whether those genes really do participate in building a competence machine. In addition, Atomic Force Microscopy will be used to take very high resolution pictures of competent bacteria to see both the competence machines and appendages. Looking at the competence machines themselves yields an understanding of how a population of cells becomes more competent. Perhaps populations become more competent when each cell makes more machines or when more cells makes machines or when each machine makes more appendages. The pictures will also indicate whether competent bacteria might use their appendages to "fish" for DNA by throwing them out and retracting them to move the DNA toward themselves. The overall goal of this research is to generate a much deeper understanding of both the genetic basis and the physical mechanisms of competence in bacteria.Broader Impacts: All the proposed research will take place in collaboration with undergraduate students. The PIs have a strong track record of involving undergraduates in research, having collectively worked with 108 students in ten years each at Colorado College. Many of these students were women and minorities, and the PIs actively recruit such students. The PIs are a physicist and a biologist in collaboration, and the dozen students expected to conduct research in their labs on this project will reflect this same combination of majors. In addition, the PIs developed a biophysics course for first-year students based on the research, which culminates with a project in which the students prepare a bacterial sample, image it with atomic force microscopy, and then write a journal-style paper to present their research, thus giving them an experiential taste of scientific research. This experience will be offered to 48 first-year students during the term of the award.

智力优势：细菌有一层类似于人类皮肤的覆盖膜，旨在将其内部成分保持在里面，并将异物排除在外。 一些细菌已经发展出了跨膜输入外源DNA并将其整合到自己基因组中的能力。 这种能力被称为自然转化或能力。 由于有能力的细菌可以将自己的天然DNA输入动物DNA，因此它们可以在压力环境中快速适应，例如在抗生素存在的情况下。 这个研究项目是为了更好地了解细菌如何能够找到DNA并将其穿过细胞膜。 目前已知的是，一些细菌可以制造称为IV型皮利的结构，这种结构由穿过它们的膜的孔组成，并且相关的长附属物可以通过这些孔向外突出。 IV型皮利被细菌用来拉动自己穿过表面，基本上使用附属物作为可伸缩的抓钩。 据信，负责能力的机制在结构上类似于IV型皮利。 这种相似性提出了两个假设：第一，构建能力机器的基因组必须与构建IV型皮利的基因组相似;第二，能力机器执行与IV型皮利相似的行为，尽管目的不同。这项研究将使用IV型皮利基因来识别潜在的能力基因，然后评估这些基因是否真的参与构建能力机器。 此外，原子力显微镜将用于拍摄非常高分辨率的胜任细菌照片，以查看胜任机器和附属物。 通过观察能力机器本身，我们可以理解细胞群是如何变得更有能力的。 也许当每个细胞制造更多的机器时，或者当更多的细胞制造机器时，或者当每个机器制造更多的附属物时，种群变得更有能力。 这些照片还将表明，有能力的细菌是否可能使用它们的附属物来“钓”DNA，方法是将它们扔出去，然后缩回，将DNA移向它们自己。 这项研究的总体目标是产生一个更深入的理解的遗传基础和细菌的能力的物理机制。更广泛的影响：所有拟议的研究将与本科生合作进行。PI在让本科生参与研究方面有着良好的记录，在科罗拉多学院的108名学生中，每名学生在10年内都有共同的工作经历。这些学生中有许多是妇女和少数民族，公共机构积极招收这些学生。PI是一个物理学家和一个生物学家的合作，十几个学生预计在他们的实验室进行研究，这个项目将反映出同样的专业组合。此外，PI根据研究为一年级学生开发了生物物理学课程，该课程以学生准备细菌样本，用原子力显微镜对其进行成像，然后写一篇期刊式论文来展示他们的研究，从而让他们体验科学研究。这种经验将提供给48个一年级学生在该奖项的任期。