Pervasive RNA editing among hornwort rbcL transcripts except Leiosporoceros
Pervasive RNA editing among hornwort rbcL transcripts except Leiosporoceros
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DOI：
10.1007/s00239-004-0146-0
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发表时间：
2005-11-01
影响因子：
3.9
通讯作者：
Moore, FBG
中科院分区：
文献类型：
--
作者：
Duff, RJ;Moore, FBG
影响叶绿体和线粒体基因组的RNA编辑已经在陆地植物的所有主要分支中被鉴定。编辑位点的频率在谱系之间变化很大，但金鱼藻在其叶绿体和线粒体基因组中的编辑倾向方面表现出极端。从7个分类学上不同的金鱼藻rbcL序列的cDNA序列结合调查的13个额外的DNA序列的潜在编辑的网站证明存在62个编辑的网站，并预测至少10个额外的网站。这72个总编辑位点代表43个C-to-U和28个U-to-C核苷酸转换，其中1个位点表现出两个方向的编辑。除了一个例外，所有分类群都经过了大量编辑，每个分类群都有20到34个编辑过的位点。然而，一个单一的样本，Leiosporoceros，缺乏编辑的网站。金鱼藻的系统发育重建的结果在模糊的决议Leiosporoceros取决于编辑的网站是否保持或消除的分析。根据Leiosporoceros与金鱼藻的关系推断，至少有两种解释可以解释金鱼藻中普遍编辑的起源和维持。Leiosporoceros中编辑位点的缺失可能代表金鱼藻共同祖先中编辑能力的缺失或低水平，如Leiosporoceros所代表的，或者在该组中的主要多样化事件之后在该谱系中失去编辑位点。
RNA editing affecting chloroplast and mitochondrial genomes has been identified in all major clades of land plants. The frequency of edited sites varies greatly between lineages but hornworts represent an extreme in propensity for editing in both their chloroplast and mitochondrial genomes. cDNA sequences from seven taxonomically diverse hornwort rbcL sequences combined with a survey of 13 additional DNA sequences for potential edited sites demonstrate the presence of 62 edited sites and predict a minimum of 10 additional sites. These 72 total edited sites represent 43 C-to-U and 28 U-to-C nucleotide conversions, with 1 site exhibiting editing in both directions. With one exception, all taxa are heavily edited, with each having from 20 to 34 edited sites. However, a single sample, Leiosporoceros, is shown to lack edited sites. Phylogenetic reconstruction of hornworts results in ambiguous resolution of Leiosporoceros depending on whether edited sites are maintained or eliminated from the analyses. Depending on the inferred relationship of Leiosporoceros to the hornworts, at least two explanations for the origin and maintenance of pervasive editing in hornworts are possible. The absence of edited sites in Leiosporoceros could represent either the absence or a low level of editing ability in the common ancestor of hornworts, as represented by Leiosporoceros, or the loss of editing sites in this lineage after the primary diversification events in the group.