Systematics and Evolution of Photobacterium, A Clade of Luminous Bacteria

这个项目寻求通过DNA序列分析来表征细菌属发光菌成员之间的进化关系。这些细菌在世界海洋中非常常见，它们将海洋动物定居为良性皮肤或肠道居民，在某些情况下会导致疾病，在其他情况下，根据细菌的发光情况与动物形成有益的共生关系。尽管这类细菌在世界范围内的分布和对环境的重要性，但如何区分一种发光细菌，有多少不同的种类，以及应该用什么标准来定义发光细菌物种，这些都是悬而未决的问题，这是所有细菌群体共同的情况，阻碍了生物医学、工业和基础科学的许多领域的进步。为了解决这些问题，将从海洋栖息地分离出基因上不同的发光菌，通过DNA指纹鉴定。从这些细菌中，选择几个基因进行测序和分析，以重建它们的进化史，并建立定义发光菌物种的DNA序列标准。该项目将对理解DNA序列差异的性质和程度产生广泛的科学影响，这些差异决定了不同细菌是否属于不同的物种。该项目的序列信息将通过公共数据库提供。该项目为学生参与者提供了系统学、微生物生物学和共生领域的培训，这些科学主题和该项目的具体成果将被纳入密歇根大学教授的微生物生物学本科课程。更广泛地说，一个为普通公众、K-12课堂环境和普通科学界设计的可公开访问的网站将提供关于发光菌的这个项目的信息，强调其不同成员的自然历史、生态分布和环境活动。

This project seeks to characterize, through DNA sequence analysis, the evolutionary relationships among members of the bacterial genus Photobacterium. These bacteria are very common in the world's oceans, colonizing marine animals as benign skin or intestinal inhabitants, in some cases causing disease, in others forming beneficial symbiotic associations with the animals based on the bacterium's luminescence. Despite the worldwide distribution and environmental importance of this group of bacteria, what distinguishes one kind of Photobacterium from another, how many different kinds there are, and what criteria should be used to define a Photobacterium species are unresolved problems, a situation that is common to all bacterial groups and that impedes progress in many areas of biomedicine, industry, and basic science. To resolve these problems, genetically different kinds of Photobacterium, identified by DNA fingerprinting, will be isolated from marine habitats. From these bacteria, several genes, chosen for their ability to reveal evolutionary relationships for members of the group, will be sequenced and the sequences analyzed to reconstruct their evolutionary history and establish DNA sequence criteria for defining a Photobacterium species.This project will have a wide scientific impact on understanding the nature and extent of the differences in DNA sequence that determine whether different bacteria belong to different species. The sequence information from this project will be made available through public databases. The project provides training to student participants in the areas of systematics, microbial biology and symbiosis, and these scientific themes and specific results from the project will be incorporated into undergraduate courses taught at the University of Michigan in microbial biology. More broadly, a publicly accessible web site designed for the general public, the K-12 classroom environment, and the general science community will make available information from this project on Photobacterium, emphasizing the natural history, ecological distributions, and environmental activities of its different members.