Horizontal Gene Transfer in Multicellular Eukaryotes

多细胞真核生物中的水平基因转移

• 批准号: 6875514
• 负责人: JEFFREY D PALMER
• 金额: $ 38.99万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6875514
• 关键词: angiosperms; biological models; evolution; genetic recombination; genome; high throughput technology; mitochondrial DNA; nucleic acid sequence; plant genetics; polymerase chain reaction

DESCRIPTION (provided by applicant): Horizontal gene transfer (HGT) is now recognized as a major evolutionary genetic force driving genomic and phenotypic change in the microbial world -- throughout prokaryotes and in many unicellular eukaryotes (all phagotrophic protists). We and others recently discovered the first evidence for widespread HGT within any group of multicellular eukaryotes, finding that horizontal transfer of mitochondrial genes in plants is both frequent and recent. Many of these transfers yield mitochondrial gene duplications (of vertically and horizontally transmitted homologs), whereas others lead to strikingly chimeric genes (part horizontal/part vertical) or repopulate the genome with genes previously transferred to the nucleus. Some of the transferred genes are intact, expressed, and probably functional. One mitochondrial genome has already been identified with multiple, perhaps many horizontally acquired genes. The goal of this study is to build on these exciting findings and conduct the first comprehensive and rigorous study of HGT in multicellular eukaryotes. Because HGT is a fundamental but poorly understood process in genome evolution, these studies will provide an important new perspective on genome structure and function. The maintenance of an intact, functioning genome is critical for human health, and understanding mechanisms of gene exchange is important to the development of gene therapy. This project focuses on plant mitochondrial genomes because their exceptional propensity for HGT and several other attributes make them a model system for investigating HGT in eukaryotes. Studies include targeted macroarray screens of 4000 plants, all-gene sequencing in 200 diverse plants, whole-genome sequencing in 15 plants with exceptionally extensive HGT, and various follow-up studies on specific cases of high interest from the above. Results will address numerous questions concerning rates, patterns, extents, chimeric consequences, donor/recipient relationships, functionality, and mechanisms of HGT across many lineages of plant mitochondrial genomes. Certain of the mechanistic studies follow from emerging evidence suggesting that certain plants and genes are unusually prone to HGT and that a common mechanism of transfer is physical penetration between parasitic plants and their host plants.

描述（由申请人提供）：水平基因转移（HGT）现在被认为是驱动微生物世界基因组和表型变化的主要进化遗传力量——遍及原核生物和许多单细胞真核生物（所有吞噬性原生生物）。我们和其他人最近发现了在任何多细胞真核生物群体中广泛存在 HGT 的第一个证据，发现植物中线粒体基因的水平转移既频繁又是最近发生的。其中许多转移产生线粒体基因重复（垂直和​​水平转移的同源物），而其他转移则导致惊人的嵌合基因（部分水平/部分垂直）或用先前转移到细胞核的基因重新填充基因组。一些转移的基因是完整的、表达的并且可能具有功能。一个线粒体基因组已被鉴定为具有多个、也许是许多水平获得的基因。 这项研究的目标是在这些令人兴奋的发现的基础上，对多细胞真核生物中的 HGT 进行首次全面而严格的研究。由于 HGT 是基因组进化中一个基本但人们知之甚少的过程，因此这些研究将为基因组结构和功能提供重要的新视角。维持完整、功能正常的基因组对于人类健康至关重要，了解基因交换机制对于基因治疗的发展也很重要。 该项目重点关注植物线粒体基因组，因为它们对 HGT 的特殊倾向和其他几个属性使它们成为研究真核生物中 HGT 的模型系统。研究包括 4000 种植物的靶向宏阵列筛选、200 种不同植物的全基因测序、15 种具有极其广泛的 HGT 的植物的全基因组测序，以及针对上述高度关注的特定案例的各种后续研究。结果将解决许多问题，涉及植物线粒体基因组许多谱系中 HGT 的速率、模式、范围、嵌合后果、供体/受体关系、功能和机制。某些机制研究源于新出现的证据，表明某些植物和基因异常容易发生 HGT，并且常见的转移机制是寄生植物与其寄主植物之间的物理渗透。