The complete nucleotide sequence and RNA editing content of the mitochondrial genome of rapeseed (Brassica napus L.):: comparative analysis of the mitochondrial genomes of rapeseed and Arabidopsis thaliana
The complete nucleotide sequence and RNA editing content of the mitochondrial genome of rapeseed (Brassica napus L.):: comparative analysis of the mitochondrial genomes of rapeseed and Arabidopsis thaliana
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DOI：
10.1093/nar/gkg795
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发表时间：
2003-10-15
影响因子：
14.9
通讯作者：
Handa, H
中科院分区：
文献类型：
--
作者：
Handa, H
甘蓝型油菜(Brassica napus L.)进行了序列测定，并与拟南芥进行了比较。全基因组221 853个核苷酸，包括34个蛋白质编码基因、3个rRNA基因和17个tRNA基因。这一基因含量与拟南芥几乎完全相同。然而，rps14基因在拟南芥中是一个假基因，在油菜中是完整的。另一方面，与拟南芥相比，油菜种子中缺失了5个tRNA基因，尽管这两个十字花科植物中线粒体编码的tRNA物种是相同的。以油菜线粒体基因组序列为基础，对RNA编辑事件进行了系统研究。在ORF中总共发现了427个C到U的转换，这与拟南芥中的数量(441个位点)几乎相同。基因序列和内含子结构大部分是保守的(蛋白质编码区的相似性超过99%)；然而，油菜和拟南芥只有358个编辑点(占总编辑量的83%)。非编码区在两种植物中大多是不同的。分别有三分之一(约78.7kb)和三分之二(约223.8 kb)的油菜籽和拟南芥线粒体基因组不能相互比对，并且这些区域中的大多数与数据库中登记的序列没有任何同源性。对油菜籽和拟南芥线粒体基因组的比较分析结果表明，高等植物线粒体在编码序列方面极其保守，在RNA编辑方面略显保守，但植物线粒体DNA的非编码部分在结构变化、序列获取和/或序列丢失方面具有极强的动态性。
The entire mitochondrial genome of rapeseed (Brassica napus L.) was sequenced and compared with that of Arabidopsis thaliana. The 221 853 bp genome contains 34 protein-coding genes, three rRNA genes and 17 tRNA genes. This gene content is almost identical to that of Arabidopsis. However the rps14 gene, which is a pseudo-gene in Arabidopsis, is intact in rapeseed. On the other hand, five tRNA genes are missing in rapeseed compared to Arabidopsis, although the set of mitochondrially encoded tRNA species is identical in the two Cruciferae. RNA editing events were systematically investigated on the basis of the sequence of the rapeseed mitochondrial genome. A total of 427 C to U conversions were identified in ORFs, which is nearly identical to the number in Arabidopsis (441 sites). The gene sequences and intron structures are mostly conserved (more than 99% similarity for protein-coding regions); however, only 358 editing sites (83% of total editings) are shared by rapeseed and Arabidopsis. Non-coding regions are mostly divergent between the two plants. One-third (about 78.7 kb) and two-thirds (about 223.8 kb) of the rapeseed and Arabidopsis mitochondrial genomes, respectively, cannot be aligned with each other and most of these regions do not show any homology to sequences registered in the DNA databases. The results of the comparative analysis between the rapeseed and Arabidopsis mitochondrial genomes suggest that higher plant mitochondria are extremely conservative with respect to coding sequences and somewhat conservative with respect to RNA editing, but that non-coding parts of plant mitochondrial DNA are extraordinarily dynamic with respect to structural changes, sequence acquisition and/or sequence loss.