International Research Center of Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.
Mitochondrion. 2011 Mar;11(2):273-8. doi: 10.1016/j.mito.2010.10.003. Epub 2010 Oct 31.
Apicomplexan parasites of the genus Plasmodium, pathogens causing malaria, and the genera Babesia and Theileria, aetiological agents of piroplasmosis, are closely related. However, their mitochondrial (mt) genome structures are highly divergent: Plasmodium has a concatemer of 6-kb unit and Babesia/Theileria a monomer of 6.6- to 8.2-kb with terminal inverted repeats. Fragmentation of ribosomal RNA (rRNA) genes and gene arrangements are remarkably distinctive. To elucidate the evolutionary origin of this structural divergence, we determined the mt genome of Eimeria tenella, pathogens of coccidiosis in domestic fowls. Analysis revealed that E. tenella mt genome was concatemeric with similar protein-coding genes and rRNA gene fragments to Plasmodium. Copy number was 50-fold of the nuclear genome. Evolution of structural divergence in the apicomplexan mt genomes is discussed.
疟原虫属的顶复门寄生虫、引起疟疾的病原体，以及巴贝西虫属和泰勒虫属，是导致梨形虫病的病原，它们密切相关。然而，它们的线粒体 (mt) 基因组结构高度不同：疟原虫有一个 6kb 单位的串联体，而巴贝斯虫/泰勒虫则是一个 6.6-8.2kb 的单体，具有末端反向重复序列。核糖体 RNA (rRNA) 基因的片段化和基因排列是显著不同的。为了阐明这种结构差异的进化起源，我们确定了家禽球虫病病原体柔嫩艾美耳球虫的 mt 基因组。分析表明，柔嫩艾美耳球虫的 mt 基因组是串联体，与疟原虫具有相似的蛋白质编码基因和 rRNA 基因片段。拷贝数是核基因组的 50 倍。讨论了顶复门线粒体基因组结构差异的进化。
