Horizontal Gene Transfer in Multicellular Eukaryotes

多细胞真核生物中的水平基因转移

基本信息

批准号：
7348367
负责人：
JEFFREY D PALMER
金额：
$ 39.01万
依托单位：
TRUSTEES OF INDIANA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-02-01 至 2011-01-31
项目状态：
已结题

项目摘要

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）现在被认为是微生物世界中的主要进化遗传力驱动基因组和表型变化 - 在多头核酸盐和许多单细胞真核生物（所有吞噬嗜性生物）中。我们和其他人最近发现了任何一组多细胞真核生物中广泛的HGT的第一个证据，发现植物中线粒体基因的水平转移既经常又是最近的。这些转移中的许多转移产生了线粒体基因的重复（垂直和水平传播的同源物），而其他转移则导致嵌合基因（部分水平/部分垂直）或用先前转移到核的基因重塑基因组。一些转移的基因完整，表达且可能功能性。一个线粒体基因组已经被鉴定出多个，也许是许多水平获得的基因。这项研究的目的是建立这些令人兴奋的发现，并在多细胞真核生物中进行HGT的首次全面而严格的研究。由于HGT是基因组进化中的基本但知之甚少的过程，因此这些研究将为基因组结构和功能提供重要的新观点。保持完整，功能性基因组对于人类健康至关重要，理解基因交换的机制对于基因治疗的发展很重要。该项目的重点是植物线粒体基因组，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种植物的靶向大型阵列筛选，200种不同植物中的全基因测序，在15种植物中进行全基因组测序，具有异常广泛的HGT，以及有关上述较高兴趣的特定情况的各种后续研究。结果将解决有关植物线粒体基因组的许多谱系中HGT的HGT的速率，模式，范围，嵌合后果，供体/受体关系，功能和机制的许多问题。某些机械研究来自新兴的证据，表明某些植物和基因异常容易出现HGT，并且转移的常见机制是寄生植物及其宿主植物之间的物理渗透。