The cyanobacterial origin and vertical transmission of the plastid tRNALeu group-I intron
The cyanobacterial origin and vertical transmission of the plastid tRNALeu group-I intron
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DOI：
10.1007/s002940050002
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发表时间：
2000-01-01
期刊：
影响因子：
2.5
通讯作者：
Bhattacharya, D
中科院分区：
文献类型：
--
作者：
Besendahl, A;Qiu, YL;Bhattacharya, D
我们调查了蓝藻和几个叶绿体基因组中位于tRNAL(Leu)基因反密码子环中的I组内含子的分布和系统发育。Southern-Blot和PCR分析表明，在所检测的330种陆地植物中都存在tRNAL(Leu)内含子。在所研究的九种轮藻中，除了一种外，所有的藻类中都发现了该内含子，并进行了测序。相反，聚合酶链式反应分析表明，tRNAL(Leu)组-I内含子在红藻、隐藻和触藻中不存在，尽管它存在于异体藻系的三个成员中。对该内含子的系统发育分析表明，该内含子存在于蓝藻的祖先中，它们分别是红藻门、绿藻门和水藻门。它在叶绿体中的分布与严格垂直传播的历史相一致，在陆地植物中没有损失，在绿藻中损失了几次，在红藻及其次生衍生物中几乎无处不在地损失。
We have surveyed the distribution and reconstructed the phylogeny of the group-I intron that is positioned in the anticodon loop of the tRNAL(Leu) gene in cyanobacteria and several plastid genomes. Southern-blot and PCR analyses showed that the tRNAL(Leu) intron is found in all 330 land plants that were examined. The intron was also found, and sequenced, in all but one of nine charophycean algae examined. Conversely, PCR analyses showed that the tRNAL(Leu) group-I intron is absent from the red, cryptophyte and haptophyte algae, although it is present in three members of the heterokont lineage. Phylogenetic analyses of the intron indicate that it was present in the cyanobacterial ancestor of the three primary plastid lineages, the Rhodophyta, Chlorophyta, and Glaucocystophyta. Its present-day distribution in plastids is consistent with a history of strictly vertical transmission, with no losses in land plants, several losses among green algae, and nearly pervasive loss in the Rhodophyta and its secondary derivatives.