Evolutionary Dynamics of Chloroplast DNA

叶绿体 DNA 的进化动力学

• 批准号: 8906129
• 负责人: Brook Milligan
• 金额: $ 22.28万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-10-15 至 1994-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8906129&HistoricalAwards=false
• 关键词: Evolutionary; Dynamics; Chloroplast; DNA

Evolutionary biology involves two major processes: the origin of genetic variants in a population, and the genetic differentiation of populations and species. Understanding both of these processes is critical to managing the earth's natural resources for sustained agriculture, as well as for answering basic questions concerning life itself. Since these two processes apply to all genetic traits- including the three plant genomes (nuclear, mitochondrial and chloroplast)- this framework serves to focus the research proposed here. In particular, this research concerns the origin of genetic diversity in the chloroplast genome of higher plants. Previous studies of chloroplast DNA evolution have often compared distantly rated groups of plants and observed structural rearrangement of the genome. From these data, mechanisms have been inferred to explain the origin of novel genotypes; however, no direct studies of those mechanisms have been attempted. As a result, much about the origin of genetic diversity in the chloroplast genome of higher plants is unknown. The proposed research aims to study two possible mechanisms involved in the origin of new chloroplast genotypes. Using a unique set of dispersed repeated elements located in the chloroplast genome of some clovers, plants in the genus Trifolium, Dr. Milligan will examine both mechanisms. By studying the genomic structure in several closely related species with differing numbers of repeats, he will be able to identify whether or not rearrangements are associated with the repeats. By sequencing different copies of the repeats he will be able to detect whether nonreciprocal recombination has occurred. This more direct study of the origin of genetic diversity in the chloroplast genome of higher plants will greatly increase our understanding of the mechanisms involved. not only will this provide information important to our basic understanding of evolution, but it may also provide a basis for modifying the genome in the future. since the plant chloroplast is responsible for photosynthesis, modifications of the genome may prove to be an important tool in the future agricultural efforts.

进化生物学涉及两个主要过程：种群中遗传变异的起源，以及种群和物种的遗传分化。了解这两个过程对于管理地球上可持续农业的自然资源以及回答有关生命本身的基本问题至关重要。由于这两个过程适用于所有的遗传特征--包括三个植物基因组(核、线粒体和叶绿体)--这个框架是这里提出的研究的重点。特别是，这项研究涉及高等植物叶绿体基因组遗传多样性的起源。以前对叶绿体DNA进化的研究经常比较遥远的植物类群，并观察到基因组的结构重排。从这些数据中，已经推断出机制来解释新的基因类型的起源；然而，还没有尝试对这些机制进行直接研究。因此，关于高等植物叶绿体基因组中遗传多样性的起源尚不清楚。这项拟议的研究旨在研究与新的叶绿体基因型起源有关的两种可能机制。米利根博士将利用位于三叶草属植物叶绿体基因组中的一组独特的分散重复的元素来研究这两种机制。通过研究几个具有不同重复次数的密切相关物种的基因组结构，他将能够确定重排是否与重复有关。通过对重复序列的不同拷贝进行测序，他将能够检测到是否发生了非互惠重组。这种对高等植物叶绿体基因组遗传多样性起源的更直接的研究将极大地增加我们对相关机制的理解。这不仅将为我们对进化的基本理解提供重要的信息，还可能为未来修改基因组提供基础。由于植物叶绿体负责光合作用，基因组的修改可能被证明是未来农业努力的重要工具。