a1 College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province 410128, PR China
a2 State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, CAAS, Lanzhou, Gansu Province 730046, PR China
a3 College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province 510642, PR China
a4 Department of Veterinary Medicine, Guangdong Ocean University, Zhanjiang, Guangdong Province 524088, PR China
a5 College of Animal Science and Technology, Yunnan Agricultural University, Kunming, Yunnan Province 650201, PR China
Sequence variability in two mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 4 (nad4), and internal transcribed spacer (ITS) of rDNA among and within three cestodes, Spirometra erinaceieuropaei, Taenia multiceps and Taenia hydatigena, from different geographical origins in China was examined. A portion of the cox1 (pcox1), nad4 genes (pnad4) and the ITS (ITS1+5.8S rDNA+ITS2) were amplified separately from individual cestodes by polymerase chain reaction (PCR). Representative amplicons were subjected to sequencing in order to estimate sequence variability. While the intra-specific sequence variations within each of the tapeworm species were 0–0.7% for pcox1, 0–1.7% for pnad4 and 0.1–3.6% for ITS, the inter-specific sequence differences were significantly higher, being 12.1–17.6%, 18.7–26.2% and 31–75.5% for pcox1, pnad4 and ITS, respectively. Phylogenetic analyses based on the pcox1 sequence data revealed that T. multiceps and T. hydatigena were more closely related to the other members of the Taenia genus, and S. erinaceieuropaei was more closely related to the other members of the Spirometra genus. These findings demonstrated clearly the usefulness of mtDNA and rDNA sequences for population genetic studies of these cestodes of socio-economic importance.
(Received February 11 2011)
(Accepted June 07 2011)
(Online publication July 12 2011)
† R.S. Dai and G.H. Liu contributed equally to this work.