Distribution of introns in the mitochondrial gene nad1 in land plants:: phylogenetic and molecular evolutionary implications
Distribution of introns in the mitochondrial gene nad1 in land plants:: phylogenetic and molecular evolutionary implications
复制标题
DOI：
10.1016/j.ympev.2003.12.013
复制
发表时间：
2004-07-01
影响因子：
4.1
通讯作者：
Qiu, YL
中科院分区：
文献类型：
--
作者：
Dombrovska, O;Qiu, YL
对46种不同的陆地植物进行了线粒体基因NADL内含子的测序。共发现7个内含子，均属于第II类，其中2个为本研究新发现。所有研究的13种苔类植物都不含内含子，情况与绿藻相同。然而，苔藓和金鱼藻各自共享一个内含子，与维管植物共享另一个内含子。这些内含子的分布模式与苔类植物代表最基本的陆地植物的假说相一致，并且这两个内含子是在苔类植物分化后在苔类-角菜-维管植物的共同祖先中获得的。金鱼藻也有自己独特的内含子。第四个内含子仅见于木贼属、马尾草科、蛇舌草属、紫薇属、铁线蕨属和铁线蕨属，可能来源于它们的共同祖先，支持单系化。以前在被子植物和少数蕨类植物中具有特征的三个内含子现在都延伸到了番茄类动物，很可能是在维管植物的共同祖先中获得的。内含子序列的系统发育分析恢复了植物的拓扑结构，表明内含子都是垂直遗传的。所有7个NADL第二类内含子都显示出广泛的系统发育分布模式，其中最窄的是念珠藻和角藻，其谱系至少可以追溯到泥盆纪(3.45亿年前)和志留纪(4.35亿年前)。因此，这些内含子一定是在陆地植物进化的早期阶段通过古老的转位事件入侵了基因。在Haplomitrium Dedecek.、Takaki Hatt的NADL中观察到潜在的大量RNA编辑。&Inoue，Hornworts，Isoetes L.，Ophioglossion，Asplum。对第二类内含子提出了新的命名方法。(C)2004 Elsevier Inc.保留所有权利。
Forty-six species of diverse land plants were investigated by sequencing for their intron content in the mitochondrial gene nadl. A total of seven introns, all belonging to group II, were found, and two were newly discovered in this study. All 13 liverworts examined contain no intron, the same condition as in green algae. Mosses and hornworts, however, share one intron by themselves and another one with vascular plants. These intron distribution patterns are consistent with the hypothesis that liverworts represent the basal-most land plants and that the two introns were gained in the common ancestor of mosses-hornworts-vascular plants after liverworts had diverged. Hornworts also possess a unique intron of their own. A fourth intron was found only in Equisetum L., Marattiaceae, Ophioglossum L., Osmunda L., Asplenium L., and Adiantum L., and was likely acquired in their common ancestor, which supports the monophyly of moniliformopses. Three introns that were previously characterized in angiosperms and a few pteridophytes are now all extended to lycopods, and were likely gained in the common ancestor of vascular plants. Phylogenetic analyses of the intron sequences recovered topologies mirroring those of the plants, suggesting that the introns have all been vertically inherited. All seven nadl group II introns show broad phylogenetic distribution patterns, with the narrowest being in moniliformopses and hornworts, lineages that date back to at least the Devonian (345 million years ago) and Silurian (435 million years ago), respectively. Hence, these introns must have invaded the genes via ancient transpositional events during the early stage of land plant evolution. Potentially heavy RNA editing was observed in nadl of Haplomitrium Dedecek., Takakia Hatt. & Inoue, hornworts, Isoetes L., Ophioglossion, and Asplenium. A new nomenclature is proposed for group II introns. (C) 2004 Elsevier Inc. All rights reserved.