The Genetic Diversity of Broad-Host-Range Plasmids in Prokaryotes

质粒是一种遗传元素，通常携带抗生素抗性因子、污染物降解基因或对其细菌宿主有用的性状编码。由于质粒可以在不同的细菌物种之间转移，它们在细菌降解环境污染物的能力和对用于治疗植物、动物和人类传染病的药物产生耐药性方面发挥着重要作用。然而，人们对这些可移动元件的遗传结构、它们编码的全部功能以及它们转移到各种生物体的限制知之甚少。为了深入了解上述问题，该基因组测序项目将重点分析100个具有广泛宿主范围的质粒（也称为BHR质粒）的基因组序列。测序的质粒来自世界各地的土壤、水和污水污泥样本。该项目包括完成质粒的测序和注释，然后对序列信息进行解释，以更好地了解质粒的进化史，以及它们在细菌染色体进化和适应新环境中的作用。在该项目期间收集的信息将为现有的微不足道的质粒序列数据库增加重要的新数据，该数据库也偏向于与人类传染病相关的质粒。这项研究是独一无二的，因为它将构成第一次全面探索由BHR质粒编码的遗传性状，并了解这些移动元件的遗传结构及其在细菌染色体间基因转移中的作用。此外，表征的质粒类型将扩展到那些在人类病原体和易培养细菌中发现的质粒。所获得的知识对于理解细菌的进化和适应具有根本性的重要性，对于开发利用质粒编码特性的策略以及评估将转基因生物引入环境的风险具有实际意义。100个BHR质粒的基因组序列将通过Genbank以及最近构建的质粒数据库提供给科学界。该项目将把这项研究与教育项目结合起来，涉及爱达荷州本科学院和当地高中的学生，特别强调美国原住民和西班牙裔学生。在常规分发渠道之外传播作品的努力将集中在网络交付上，其中将包括几个功能，旨在为中学到大学的学生、他们的老师和顾问以及公众提供有用的信息。这些特色将包括创新的信息图表、专注于“科学问题”的音频和视频播客、经常更新的博客以及与初中和高中教师分享的实验课程示例。该项目还将促进两名科学领域女教师的职业发展。

Plasmids are genetic elements that often carry antibiotic resistance factors, pollutant degradation genes or code for traits that are useful for their bacterial hosts. Because plasmids can transfer among different bacterial species, they play an important role in the ability of bacteria to degrade environmental contaminants and to become resistant to drugs used to treat infectious diseases of plants, animals and humans. However, little is known about the genetic structure of these mobile elements, the full range of functions that they encode, and the limits to which they can transfer to various organisms. To gain insight into the issues outlined above, this genome sequencing project will focus on the analysis of the genome sequences of 100 plasmids that have a broad host-range (also called BHR plasmids). The sequenced plasmids were obtained from soil, water, and sewage sludge samples from around the globe. The project includes finishing the sequencing and annotation of the plasmids, and then interpreting the sequence information to better understand the evolutionary history of plasmids, and their role in bacterial chromosome evolution and adaptation to new environments. The information collected during this project will add significant new data to the paltry plasmid sequence database that now exists, which is also skewed towards plasmids relevant to human infectious diseases. This study is unique, as it will constitute the first comprehensive expedition to discover the genetic traits encoded by BHR plasmids and to understand the genetic structure of these mobile elements and their role in gene transfer between chromosomes of bacteria. Moreover, the types of plasmids characterized will be extended beyond those that are found in human pathogens and easily cultivated bacteria. The knowledge gained will be of fundamental importance to understanding the evolution and adaptation of bacteria, and of practical significance in developing strategies to exploit plasmid encoded traits and in evaluating the risks associated with the introduction of genetically modified organisms into the environment. The genome sequences of 100 BHR plasmids will be made available to the science community through Genbank as well as through recently constructed plasmid databases. The project will integrate this research with educational programs by involving students from Idaho's undergraduate colleges and local high schools, with special emphasis on Native American and Hispanic students. Efforts to disseminate the work beyond the normal distribution channels will focus on Web delivery that will include several features designed to provide useful information for middle school through college students, their teachers and advisors as well as the public. These features will include innovative information graphics, audio and video podcasts focused on "Issues in Science", a frequently updated blog, and laboratory lesson examples to share with middle and high school teachers. This project will also enhance the careers of two women faculty in science.