CAREER: The regulation of natural transformation in Vibrio

职业：弧菌自然转化的调节

• 批准号: 1149925
• 负责人: Brian Hammer
• 金额: $ 90万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-15 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1149925&HistoricalAwards=false
• 关键词: CAREER; regulation; natural; transformation; Vibrio

Intellectual Merit: The overall goal of this research is to understand the contribution of extracellular chemical signaling in the exchange of genetic material that accelerates bacterial adaptation. Although a transient human pathogen, Vibrio cholerae is an endemic marine microbe often found attached to the exoskeleton of arthropods, which are composed of the most abundant polymer in the ocean, chitin. V. cholerae is a member of a distinctive group of bacteria shown to be naturally competent to take up extracellular DNA and incorporate this genetic material onto their chromosomes. This method of horizontal gene transfer, termed natural transformation, occurs in V. cholerae in response to two environmental signaling pathways; a chitin utilization system that results in production of a regulator (TfoX), and a cell-cell communication (Quorum Sensing; QS) system that induces production of the transcription factor (HapR). The genes and network connections that link TfoX and HapR to DNA uptake are not known. Thus, this project will address the following aims. Aim 1: To identify genes that participate in horizontal gene transfer in response to extracellular QS signal molecules and to chitin. Aim 2: To define regulatory pathways connecting QS and chitin signaling to natural transformation. Aim 3: To examine the function of natural transformation network components. Aim 4: To determine the functionality of QS- and chitin-induced pathways in diverse V. cholerae environmental isolates. The research in this proposal is designed to exploit our understanding of chitin utilization and the V. cholerae QS paradigm for the identification of novel natural transformation genes. This research will dissect the role that both habitat and genetics play in bacterial evolution. Broader Impacts: The applicant engages in teaching and service to integrate individuals in the academic community with members of the broader society in the process of modern scientific inquiry. Dr. Hammer teaches a Prokaryotic Molecular Genetics course for upper-level undergraduates and graduate students; and has established research collaborations with colleagues within the Unites States and other countries, to promote scientific and cultural exchange opportunities for his lab members. He initiated a substantial outreach program in 2009 that is expanded here, hosting a fifth grade teacher to work as a summer intern in his lab. Together Dr. Hammer and the teacher develop stimulating hands-on scientific exercises that engage ethnically diverse K-12 students in metro Atlanta. Activities are shared with local educators and will be presented at regional or national meetings including the National Science Teachers Association conference. Dr. Hammer is also an active teacher and mentor for students at all levels and post-doctoral fellows.

智力优势：这项研究的总体目标是了解细胞外化学信号在加速细菌适应的遗传物质交换中的作用。虽然霍乱弧菌是一种短暂的人类病原体，但它是一种地方性海洋微生物，经常附着在节肢动物的外骨骼上，节肢动物由海洋中最丰富的聚合物甲壳素组成。霍乱弧菌是一组独特细菌的成员，这些细菌被证明天然能够吸收细胞外DNA并将这种遗传物质整合到其染色体上。这种水平基因转移的方法，称为自然转化，发生在霍乱弧菌中，响应于两种环境信号传导途径;几丁质利用系统，导致产生调节因子（TfoX），和细胞-细胞通讯（Quorum Sensing; QS）系统，诱导产生转录因子（HapR）。将TfoX和HapR与DNA摄取联系起来的基因和网络连接尚不清楚。因此，该项目将实现以下目标。目的1：鉴定参与水平基因转移的基因，以响应细胞外QS信号分子和几丁质。目的2：确定连接QS和几丁质信号传导到自然转化的调节途径。目的3：检验自然转换网络组件的功能。目的4：确定QS和几丁质诱导的途径在不同的霍乱弧菌环境分离株中的功能。 本研究旨在利用我们对几丁质利用的理解和霍乱弧菌QS范式来鉴定新的天然转化基因。 这项研究将剖析栖息地和遗传学在细菌进化中的作用。更广泛的影响：申请人从事教学和服务，在现代科学探究的过程中，将学术界的个人与更广泛的社会成员结合起来。Hammer博士为高年级本科生和研究生教授Prophylaxis分子遗传学课程;并与美国和其他国家的同事建立了研究合作，以促进他的实验室成员的科学和文化交流机会。他在2009年发起了一个实质性的外展计划，并在这里扩大，接待了一名五年级教师在他的实验室做暑期实习生。 Hammer博士和老师一起开发了刺激性的动手科学练习，吸引了亚特兰大大都会地区种族多样的K-12学生。 活动与当地教育工作者分享，并将在区域或国家会议上介绍，包括全国科学教师协会会议。Hammer博士也是各级学生和博士后研究员的积极教师和导师。