SEQUENCING AND ANALYSIS OF THE MITOCHONDRIAL REGION OF 4.2 KB FOR THE SMALL LIVER FLUKE, OPISTHORCHIS VIVERRINI

Abstract

A mitochondrial region of 4.2 kb for 3 isolates of the small liver fluke Opisthorchis viverrini collected in Vietnam, designated as OvQN (Quang Nam), OvBDl (Binh Dinh), OvPY3 (Phu Yen) and an isolate from Thailand (OvKK), obtained using PCR strategy was cloned, sequenced and analyzed. Starting with the protein-coding nad4 and ending with a transfer RNA foraerine (trnS I), the 4.2 kb mitochondrial region contains 16 genes, including 5 protein coding genes (3' end of nad4, atp6, nad2, nodI, nadJ) and II transfer RNA genes such as trnQ, trnF. tmM, tmV, trnA, trnD. tmN. trnP, trnl, trnK and trnSI (part ofS' end). Arrangement for all of these protein-coding and transfer RNA genes is completely similar to that of the platyhelminths previously studied. Analysis of the nucleotide composition constructing this mitochondrial region indicated that all the 0. viverrini small liverfluke isolates use 44.1 - 44.3% thymine (T); 12.2 - 12.3% cytosine (C); 15.9% adenine (A); and 27.6% guanine (G) for construction of the 42 kb region. Overall A + T is 60%, and G + C is 40%, which is same as that stated in other common flatworms, except for schistosomes, to be studied up to date. This is the fIrst report about the gene order and composition of the mitochondrial genome for the small liver fluke 0. viverrini, and 3 strains of Vietnam origin which are registered in GenBank as OvQN (EU443832), OvBDI (EU44383I ), OvPY3 (EU443833).