A global picture of tRNA genes in plant genomes
A global picture of tRNA genes in plant genomes
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DOI：
10.1111/j.1365-313x.2011.04490.x
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发表时间：
2011-04-01
期刊：
影响因子：
7.2
通讯作者：
Marechal-Drouard, Laurence
中科院分区：
文献类型：
--
作者：
Michaud, Morgane;Cognat, Valerie;Marechal-Drouard, Laurence
尽管转移RNA （tRNA）在细胞生命中起着至关重要的作用，但人们对真核生物，特别是植物中tRNA基因在全基因组范围内的组织和表达知之甚少。本文分析了5种开花植物和1种绿藻中tRNA基因的含量和分布。tRNA基因含量在植物中具有同质性，且主要与基因组大小相关。核基因组中存在的tRNA假基因和细胞器样tRNA基因的数量因植物物种而异。这些假基因或类细胞器基因似乎是在进化过程中随机产生或插入的。有趣的是，我们在毛杨核基因组中发现了一个与trna相关的短穿插核元件（short interspersed nuclear elements, SINEs）新家族。在高等植物中，含有内含子的tRNA基因是罕见的，与tRNATyr和tRNAMete的编码基因相对应。相比之下，在绿藻中，超过一半的tRNA基因含有内含子。这表明绿藻和陆生植物的内含子获取方式和剪接过程存在差异。许多trna在衣藻中共转录，但在开花植物中它们大多作为一个单位转录。唯一的例外是tRNAGly-snoRNA和trname - snorna分别在双子叶和单子叶中。RNA聚合酶III有效转录tRNA基因所需的内部或外部基序在被子植物中很好地保守。还提供了线粒体和质体tRNA基因种群的简要分析。
P>Although transfer RNA (tRNA) has a fundamental role in cell life, little is known about tRNA gene organization and expression on a genome-wide scale in eukaryotes, particularly plants. Here, we analyse the content and distribution of tRNA genes in five flowering plants and one green alga. The tRNA gene content is homogenous in plants, and is mostly correlated with genome size. The number of tRNA pseudogenes and organellar-like tRNA genes present in nuclear genomes varies greatly from one plant species to another. These pseudogenes or organellar-like genes appear to be generated or inserted randomly during evolution. Interestingly, we identified a new family of tRNA-related short interspersed nuclear elements (SINEs) in the Populus trichocarpa nuclear genome. In higher plants, intron-containing tRNA genes are rare, and correspond to genes coding for tRNATyr and tRNAMete. By contrast, in green algae, more than half of the tRNA genes contain an intron. This suggests divergent means of intron acquisition and the splicing process between green algae and land plants. Numerous tRNAs are co-transcribed in Chlamydomonas, but they are mostly transcribed as a single unit in flowering plants. The only exceptions are tRNAGly-snoRNA and tRNAMete-snoRNA cotranscripts in dicots and monocots, respectively. The internal or external motifs required for efficient transcription of tRNA genes by RNA polymerase III are well conserved among angiosperms. A brief analysis of the mitochondrial and plastidial tRNA gene populations is also provided.