Tracing Processes of Genome Evolution Using Plantaginaceae

智力优势：生命的所有领域都存在着非凡的基因组多样性，但人们对塑造基因组结构和功能的进化过程知之甚少。植物的线粒体基因组在真核生物中是非常显著的：它们非常大并且高度重组，它们的核苷酸序列进化非常慢，它们的基因富含内含子，偶尔经历水平基因转移(HGT)，它们的转录本由于RNA编辑而经历了大量的修改。与大多数植物不同的是，车前属(车前科；车前目)的线粒体基因组在结构和内容上表现出严重的偏离，包括极高的替换率，内含子和RNA编辑含量的前所未有的减少，以及对HGT的敏感性增加。这些事件发生在过去的几百万年内，提供了一个难得的机会来追踪它们的进化，并在短的进化时间尺度上评估它们对基因组结构和功能的影响。将在车前科内进行比较基因组学研究，并与其他植物进行比较，以揭示该家族在替换率、内含子含量、编辑位点内容和HGT方面的完全多样性。这个项目将提供对车前草线粒体异常进化趋势的原因和后果的更多了解，这些结果应该为所有活着的有机体的基因组结构和内容的进化提供重要的洞察。更广泛的影响：PI致力于培养各种背景和技能水平的科学家，包括从高中到研究生的女性、少数民族和农村学生。这个项目将有高中生参与，他们将通过暑期研究体验参与其中。此外，还将为本科生、研究生和博士后研究员提供研究培训。外国学生交流项目将为美国学生提供进行国际实地考察的机会，并为国际学生访问PI的实验室学习分子技术提供机会。该项目的成果将通过期刊出版物、在国内和国际会议上的陈述以及在内布拉斯加州州立大学博物馆的一系列公开陈述中广泛传播。

Intellectual merit: There is extraordinary genomic diversity across all domains of life, yet little is understood about the evolutionary processes that shape genome structure and function. The mitochondrial genomes of plants are remarkable among eukaryotes: they are extremely large and highly recombinogenic, their nucleotide sequences evolve very slowly, their genes are intron-rich and occasionally undergo horizontal gene transfer (HGT), and their transcripts experience numerous modifications due to RNA editing. In contrast to most plants, the mitochondrial genomes from species in genus Plantago (Plantaginaceae; Lamiales) exhibit drastic deviations in structure and content including highly elevated substitution rates, unprecedented reductions in intron and RNA editing content, and increased susceptibility to HGT. These events have occurred within the last few million years, providing a rare opportunity to trace their evolution and to evaluate their effects on genome structure and function over a short evolutionary timescale. A comparative genomics study will be performed within the Plantaginaceae, and in comparison to other plants, to reveal the full diversity in substitution rates, intron content, edit site content, and HGT across the family. This project will provide greater understanding of the causes and consequences of the unusual evolutionary trends in Plantago mitochondria, and these results should provide significant insight into the evolution of genome structure and content in all living organisms.Broader impacts: The PI is committed to training scientists of all backgrounds and skill levels including women, minorities, and rural students from the high school to the postgraduate level. This project will involve high school students, who will participate through a summer research experience. In addition, research training will be provided for undergraduates, a graduate student, and a postdoctoral researcher. A foreign student exchange program will provide opportunities for US students to do international field work and for international students to visit the PI's lab to learn molecular techniques. Results of the project will be widely disseminated through journal publications, in presentations at national and international conferences, and as part of a series of public presentations at the University of Nebraska State Museum.