Jeon H K, Lee K H, Kim K H, Hwang U W, Eom K S
Department of Parasitology and Medical Research Institute, Chungbuk National University College of Medicine, Chongju, Chungbuk 361-763, South Korea.
Parasitology. 2005 Jun;130(Pt 6):717-26. doi: 10.1017/s0031182004007164.
The complete Taenia asiatica mitochondrial genome was amplified by long extension polymerase chain reaction (long PCR) to yield overlapping fragments that were then completely sequenced. The whole mitochondrial genome was 13 703 bp long and contained 12 protein-encoding, 2 ribosomal RNA (small and large subunits), 22 transfer RNA genes and a short non-coding region. Thus, its gene contents are like those typically found in metazoan animal mitochondrial genomes (apart from the absence of atp8). All the genes were transcribed from the same strand. The 3' end 34 bp region of nad4L overlapped with the 5' end portion of nad4. The tRNA genes were 61-69 bp long, and the secondary structures of 18 tRNAs had typical clover-leaf shapes with paired DHU arms. However, trnC, trnS1, trnS2 and trnR had unpaired DHU arms that were 7-12 bp in length. The tRNAs that transferred serine lacked a DHU arm, as is also observed in a number of parasitic platyhelminths and metazoans. However, the trematode trnRs have paired DHU arms. The T. asiatica mtDNA non-coding region was like that in other cestodes since it was composed of a short non-coding region of 72 nucleotides and a long non-coding region of 176 nucleotides separated by a trnL1/, trnS2/, trnL2/, trnR/, nad5 gene cluster. The sequences of the cox1 genes between T. asiatica and T. saginata differ by 4.6%, while the T. asiatica cob gene differs by 4.1% and 12.9% from the cob genes of T. saginata and T. solium, respectively. In conclusion, the T. asiatica mitocondrial genome should provide a resource for comparative mitochondrial genomics and systematic studies of parasitic cestodes.
通过长延伸聚合酶链反应（长PCR）扩增亚洲带绦虫完整的线粒体基因组，以产生重叠片段，然后对这些片段进行全序列测定。完整的线粒体基因组长度为13703 bp，包含12个蛋白质编码基因、2个核糖体RNA（小亚基和大亚基）、22个转运RNA基因和一个短的非编码区。因此，其基因组成与后生动物线粒体基因组中典型的组成相似（除了缺少atp8）。所有基因都从同一条链转录。nad4L的3'端34 bp区域与nad4的5'端部分重叠。转运RNA基因长度为61 - 69 bp，18个转运RNA的二级结构具有典型的三叶草形状，带有配对的DHU臂。然而，trnC、trnS1、trnS2和trnR具有未配对的DHU臂，长度为7 - 12 bp。转运丝氨酸的转运RNA缺乏DHU臂，这在许多寄生扁形虫和后生动物中也有观察到。然而，吸虫的trnR具有配对的DHU臂。亚洲带绦虫线粒体DNA的非编码区与其他绦虫的相似，因为它由一个72个核苷酸的短非编码区和一个176个核苷酸的长非编码区组成，这两个区域被一个trnL1/、trnS2/、trnL2/、trnR/、nad5基因簇隔开。亚洲带绦虫和牛带绦虫之间cox1基因的序列差异为4.6%，而亚洲带绦虫的cob基因与牛带绦虫和猪带绦虫的cob基因分别相差4.1%和12.9%。总之，亚洲带绦虫线粒体基因组应为寄生绦虫的线粒体基因组比较和系统研究提供资源。
