The mitochondrial genome map of Nelumbo nucifera reveals ancient evolutionary features.
The mitochondrial genome map of Nelumbo nucifera reveals ancient evolutionary features.
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DOI：
10.1038/srep30158
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发表时间：
2016-07-22
影响因子：
4.6
通讯作者：
Ding Y
中科院分区：
文献类型：
--
作者：
Gui S;Wu Z;Zhang H;Zheng Y;Zhu Z;Liang D;Ding Y
Nelumbo nucifera 是白垩纪晚期的进化遗迹。 N. nucifera 线粒体基因组测序对于阐明基础双子叶植物的进化特征非常重要。这里，利用单分子实时测序技术（SMRT）对N. nucifera线粒体基因组进行了测序，并在从头组装和注释后构建了线粒体基因组图谱。结果显示，N. nucifera线粒体基因组全长524,797 bp，共有63个基因，其中包括40个蛋白编码基因、3个rRNA基因和20个tRNA基因。十五个共线基因簇在不同植物物种中保守。蛋白质编码基因中大约有 700 个 RNA 编辑位点被鉴定出来。通过选择压力分析来鉴定正选择的基因。鉴定出 19 个叶绿体衍生片段，7 个 tRNA 来自叶绿体。这些结果表明，N. nucifera 线粒体基因组保留了进化上保守的特征，包括古老的基因内容和基因簇、高水平的 RNA 编辑以及低水平的叶绿体衍生片段插入。作为第一个公开的基础真双子叶植物线粒体基因组，N. nucifera线粒体基因组有助于进一步分析基础真双子叶植物的特征，并提供从基础被子植物到高级真双子叶植物的进化轨迹线索。
Nelumbo nucifera is an evolutionary relic from the Late Cretaceous period. Sequencing the N. nucifera mitochondrial genome is important for elucidating the evolutionary characteristics of basal eudicots. Here, the N. nucifera mitochondrial genome was sequenced using single molecule real-time sequencing technology (SMRT), and the mitochondrial genome map was constructed after de novo assembly and annotation. The results showed that the 524,797-bp N. nucifera mitochondrial genome has a total of 63 genes, including 40 protein-coding genes, three rRNA genes and 20 tRNA genes. Fifteen collinear gene clusters were conserved across different plant species. Approximately 700 RNA editing sites in the protein-coding genes were identified. Positively selected genes were identified with selection pressure analysis. Nineteen chloroplast-derived fragments were identified, and seven tRNAs were derived from the chloroplast. These results suggest that the N. nucifera mitochondrial genome retains evolutionarily conserved characteristics, including ancient gene content and gene clusters, high levels of RNA editing, and low levels of chloroplast-derived fragment insertions. As the first publicly available basal eudicot mitochondrial genome, the N. nucifera mitochondrial genome facilitates further analysis of the characteristics of basal eudicots and provides clues of the evolutionary trajectory from basal angiosperms to advanced eudicots.