HORIZONTAL GENE EXCHANGE AND GENOME EVOLUTION OF MYOVIRUSES IN AN AQUATIC ENVIRO

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 噬菌体负责许多细菌病原体的毒力。噬菌体编码的毒力因子包括大肠杆菌致病菌株中的滋贺毒素、霍乱弧菌中的霍乱毒素和肉毒梭菌中的肉毒神经毒素。噬菌体可以通过毒力因子的水平转移来驱动新的致病性细菌菌株的出现和进化，因此对噬菌体基因组进化的理解具有重要的公共卫生意义。该研究项目研究了水生环境中噬菌体基因组的遗传结构，动力学和进化。我们将测试的假设，目前的噬菌体多样性可以归因于最近发生的水平遗传交换事件。在Myoviridae家庭的水生噬菌体的自然社区正在开发作为一个模型系统，以解决有关噬菌体基因组进化的问题。核心病毒和宿主衍生基因正在从过去九年分离的噬菌体以及从纳拉甘塞特湾获得的新分离物中测序。生物信息学工具被用来分析这些序列：（1）构建系统发育基因和基因组树，（2）比较基因之间的相对差异率，（3）检测和测定水平基因转移事件，（4）评估在寄生虫之间以及寄生虫与其宿主之间可能的遗传交换数量。这些噬菌体携带来自其宿主、其他宿主或共同基因库的过量遗传物质的能力正在使用脉冲场凝胶电泳进行评估。本科生参与研究的各个方面。这个试点项目在夏季和学年期间对本科生进行生物医学研究中使用的关键分子遗传技术的培训。 学生将获得科学交流，实验室技术，关键仪器的使用和生物信息学的经验，因为他们完成个人项目。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Bacteriophages are responsible for the virulence of many bacterial pathogens. Phage-encoded virulence factors include the shiga toxins in pathogenic strains of Escherichia coli, the cholera toxin in Vibrio cholerae, and the botulinum neurotoxins in Clostridium botulinum. Bacteriophages can drive the emergence and evolution of new pathogenic bacterial strains by the horizontal transfer of virulence factors and thus an understanding of bacteriophage genome evolution has important public health implications. This research project examines the genetic structure, dynamics, and evolution of bacteriophage genomes in an aquatic environment. We will test the hypothesis that much of the current bacteriophage diversity can be attributed to horizontal genetic exchange events that occurred recently. A natural community of aquatic bacteriophages in the Myoviridae family is being developed as a model system to address questions about bacteriophage genome evolution. Core-viral and host-derived genes are being sequenced from bacteriophages isolated over the past nine years as well as from new isolates obtained from Narragansett Bay. Bioinformatic tools are being used to analyze these sequences to: (1) construct phylogenetic gene and genome trees, (2) compare relative rates of divergence among genes, (3) detect and date horizontal gene transfer events, and (4) assess the number of possible genetic exchanges among phages and between phages and their hosts. The capability of these bacteriophages to carry excess genetic material derived from their hosts, other phages, or a common gene pool is being assessed using pulsed field gel electrophoresis. Undergraduate students participate in all aspects of the research. This pilot project is training undergraduate students both during the summer and the academic year in key molecular genetic techniques used in biomedical research. Students will gain experience in scientific communication, laboratory techniques, use of key instrumentation, and bioinformatics as they complete individual projects.