Complete sequence of the mitochondrial genome of a diatom alga Synedra acus and comparative analysis of diatom mitochondrial genomes
Complete sequence of the mitochondrial genome of a diatom alga Synedra acus and comparative analysis of diatom mitochondrial genomes
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DOI：
10.1007/s00294-010-0293-3
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发表时间：
2010-06-01
期刊：
影响因子：
2.5
通讯作者：
Grachev, Mikhail A.
中科院分区：
文献类型：
--
作者：
Ravin, Nikolai V.;Galachyants, Yuri P.;Grachev, Mikhail A.
海洋硅藻的前两个线粒体基因组先前被报道为中心的Thalassiosira dangerana和针羽状的Phaeodactylum tricornutum。作为基因组计划的一部分，我们对淡水蚜虫羽纹硅藻尖针杆藻的完整线粒体基因组进行了测序。这个46，657 bp的mtDNA编码2个rRNA、24个tRNA和33个蛋白质。对S. acus含有三个II组内含子，两个插入cox 1基因并含有ORF，一个插入rn1基因并缺少ORF。紧凑的基因组织与存在4.9 kb长的基因间区域形成对比，该区域包含重复序列。比较三个mtDNA序列发现，这三个基因组携带相似的基因库，但一些基因的位置被重排。用硅藻和其他异鞭毛类的cox 1基因片段进行的系统发育分析产生了一个类似于来自18S RNA基因的树。硅藻线粒体DNA的内含子似乎是多系的。这项研究表明，焦磷酸测序是一种有效的方法，从硅藻线粒体基因组的完整测序，并可能很快提供有价值的信息，这一杰出的单细胞生物群体的分子生物学。
The first two mitochondrial genomes of marine diatoms were previously reported for the centric Thalassiosira pseudonana and the raphid pennate Phaeodactylum tricornutum. As part of a genomic project, we sequenced the complete mitochondrial genome of the freshwater araphid pennate diatom Synedra acus. This 46,657 bp mtDNA encodes 2 rRNAs, 24 tRNAs, and 33 proteins. The mtDNA of S. acus contains three group II introns, two inserted into the cox1 gene and containing ORFs, and one inserted into the rnl gene and lacking an ORF. The compact gene organization contrasts with the presence of a 4.9-kb-long intergenic region, which contains repeat sequences. Comparison of the three sequenced mtDNAs showed that these three genomes carry similar gene pools, but the positions of some genes are rearranged. Phylogenetic analysis performed with a fragment of the cox1 gene of diatoms and other heterokonts produced a tree that is similar to that derived from 18S RNA genes. The introns of mtDNA in the diatoms seem to be polyphyletic. This study demonstrates that pyrosequencing is an efficient method for complete sequencing of mitochondrial genomes from diatoms, and may soon give valuable information about the molecular phylogeny of this outstanding group of unicellular organisms.