HORIZONTAL GENE EXCHANGE AND GENOME EVOLUTION OF VIRUSES 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， 因此可以在其他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。这个研究项目将检查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的水平遗传交换事件之间的寄生虫和他们的主机。属于Myoviridae和Podoviridae家族的水生噬菌体的自然群落将被用作模型系统，以解决有关噬菌体基因组进化和水平基因转移频率的问题。将设计核心病毒基因以及宿主衍生基因的PCR引物。病毒和宿主衍生基因将从过去十年分离的噬菌体以及从纳拉甘塞特湾获得的新分离物中进行测序。生物信息学工具将用于分析这些序列，以：（1）构建系统发育基因和基因组树，（2）比较基因之间的相对分化率，（3）检测和测定水平基因转移事件，以及（4）评估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。本科生将参与研究的各个方面。这个试点项目将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 phage genome evolution has important public health implications. This research project will examine the genetic structure, dynamics, and evolution of phage genomes. We will test the hypothesis that much of the current phage diversity can be attributed to recent horizontal genetic exchange events among phages and their hosts. A natural community of aquatic bacteriophages belonging to the Myoviridae and Podoviridae families will be used as a model system to address questions about phage genome evolution and the frequency of horizontal gene transfer. PCR primers for core-viral genes as well as host-derived genes will be designed. Viral and host-derived genes will be sequenced from bacteriophages isolated over the past ten years as well as from new isolates obtained from Narragansett Bay. Bioinformatic tools will be 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. Undergraduate students will participate in all aspects of the research. This pilot project will train 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.