The origin and evolution of green algal and plant actins
The origin and evolution of green algal and plant actins
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DOI：
10.1093/oxfordjournals.molbev.a026109
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发表时间：
1999-02-01
影响因子：
10.7
通讯作者：
Bhattacharya, D
中科院分区：
文献类型：
--
作者：
An, SS;Möpps, B;Bhattacharya, D
绿色植物门又分为两大类：绿藻门，包括绿藻纲、绿藻纲、石藻纲。和Prasinophyceae;和Streptophyta，其中包括轮藻和所有陆地植物。在链藻门中，被子植物的肌动蛋白基因在单子叶植物和双子叶植物分离之前几乎同时彼此分离。以前的进化分析对产生这些复杂基因家族的基因复制提供了有限的见解。我们通过研究绿色藻类、蕨类植物和蕨类植物中肌动蛋白的遗传，来探讨陆地植物肌动蛋白基因的起源和多样性。部分基因组序列或编码肌动蛋白的cDNA的特征在于从Cosmarium botrytis（Zygnematales），Selaginella apoda（Selaginellales），贫血phylliphum（水龙骨科），和Psilotum triquetrum（Psilotales）。卷柏至少含有两个肌动蛋白基因。一个序列（Ac 2）在一组蕨类序列内发散，所述蕨类序列还包括Psilotum Ac 1肌动蛋白基因和一个裸子植物序列（苏铁Cycas revoluta Cyc 3）。该分支位于被子植物肌动蛋白基因辐射之外。第二个卷柏序列（Ac 1）是所有剩余陆地植物肌动蛋白序列的姐妹，尽管该树的这一部分中的内部分支是：短.在系统发育分析中使用完整的肌动蛋白编码区为被子植物肌动蛋白分为两类提供了支持。N-末端“签名”序列分析支持这些分组。一类（VEG）包括通常在营养结构中表达的肌动蛋白基因。第二类（REP）包括肌动蛋白基因，其在营养肌动蛋白中追踪其祖先，并且包含主要在生殖结构中表达的成员。肌动蛋白基因内内含子位置的分析表明，卷柏属和鼓藻属的序列都含有在链藻门的许多成员中发现的保守的20-3、152-1和356-3内含子。此外，鼓藻肌动蛋白基因在76-1位含有一个新的内含子。
The Viridiplantae are subdivided into two groups: the Chlorophyta, which includes the Chlorophyceae, Trebouxiophyceae, Ulvophyceae. and Prasinophyceae; and the Streptophyta, which includes die Charophyceae and all land plants. Within the Streptophyta, the actin genes of the angiosperms diverge nearly simultaneously fi om each other before the separation of monocots and dicots. Previous evolutionary analyses have provided limited insights into the gene duplications that have produced these complex gene families. We address the origin and diversification of land plant actin genes by studying the phylogeny of actins within the green algae, ferns, and fern allies. Partial genomic sequences or cDNAs encoding actin were characterized from Cosmarium botrytis (Zygnematales), Selaginella apoda (Selaginellales), Anemia phyllitidis (Polypodiales), and Psilotum triquetrum (Psilotales). Selaginella contains at least two actin genes. One sequence (Ac2) diverges within a group of fern sequences that also includes the Psilotum Ac1 actin gene and one gymnosperm sequence (Cycas revoluta Cyc3). This clade is positioned outside of the angiosperm actin gene radiation. The second Selaginella sequence (Ac1) is the sister to all remaining land plant actin sequences, although the internal branches in this portion of the tree are ver!: short. Use of complete actin-coding regions in phylogenetic analyses provides support for the separation of angiosperm actins into two classes. N-terminal "signature" sequence analyses support these groupings. One class (VEG) includes actin genes that are often expressed in vegetative structures. The second class (REP) includes actin genes that trace their ancestry within the vegetative actins and contains members that are largely expressed in reproductive structures. Analysis of intron positions within actin genes shows that sequences from both Selaginella and Cosmarium contain the conserved 20-3, 152-1, and 356-3 introns found in many members of the Streptophyta. In addition, the Cosmarium actin gene contains a novel intron at position 76-1.