Microbial Genome Sequencing: High-Resolution Phylogenomics of Halophilic Archaea

嗜盐古细菌具有在高盐环境（通常超过3M NaCl）中生存的共同能力，但也具有多种代谢活动，其中一些已经在生物技术中得到了应用。Facciotti博士（加州大学戴维斯分校）和合作者Eisen博士（加州大学戴维斯分校）以及博士后学者Darling博士正在对古细菌家族的几个成员进行全面测序，以促进我们对微生物基因组组织和进化的理解，并为系统生物学的努力提供基础，以实验方式查询微生物生物化学，生理学，代谢，发育和细胞生物学的新方面。本研究的关键方面是，这些基因组序列将提供足够的系统发育家族覆盖范围（无论是广度还是深度），从而使基因组组织的比较研究以及遗传信息的交换和重组成为可能。因为被提议进行测序的生物已经适应了高盐环境中的生活，这些模型系统的发展也将直接影响我们对耐盐性的理解，这一问题在耐盐和抗旱粮食作物的发展中仍然具有重要意义。pi还打算解决生物物种概念是否可以应用于古细菌。该项目还将研究古细菌DNA复制，这与真核和原核生物基因组复制和基因组组织有共同的方面。由于嗜盐菌是课堂使用的优秀模型系统，pi打算为高中教师和学生开发一个新的教育模块来学习基因组序列分析。pi将通过www.halophiles.org免费提供此模块。

Halophilic archaea share the common ability to live in hypersaline environments (typically in excess of 3M NaCl) but also possess a diverse set of metabolic activities, some of which have already found their way into biotechnological applications. Several members of the archaeal family Halobacteriaceae are being fully sequenced by Dr. Facciotti (UC Davis) and collaborators Dr. Eisen (UC Davis) and postdoc scholar Dr. Darling to advance our understanding of genome organization and evolution of microbial genomes and to provide a foundation for systems biology efforts to experimentally query novel aspects of microbial biochemistry, physiology, metabolism, development and cellular biology. The critical aspect to this study is that these genome sequences will provide sufficient coverage of this phylogenetic family (both in breadth and depth) so that comparative studies on the organization of genomes and the exchange and reshuffling of genetic information will become possible. Because the organisms proposed for sequencing have adapted for life in hypersaline environments, the development of these as model systems will also directly shape our understanding of salt tolerance, an issue that continues to be of great relevance in the development of salt and drought resistant food crops. The PIs also intend to address whether the biological species concept can be applied to archaea. The project will also investigate archaeal DNA replication, which shares aspects with both eukaryotic and prokaryotic genome replication, and genome organization. Since halophiles are excellent model systems for classroom use, the PIs intend to develop a new educational module with high school teachers and students to learn genome sequence analysis. The PIs will make this module freely available via www.halophiles.org.