Orientobilharzia turkestanicum is grouped within African schistosomes based on phylogenetic analyses using sequences of mitochondrial genes

Abstract

In the present study, samples representing Orientobilharzia turkestanicum from cattle, sheep, and cashmere goat in Daqing District, Heilongjiang Province, China, were characterized and grouped genetically by sequences of mitochondrial cytochrome c oxidase subunit 1 gene (cox1) and nicotinamide adenine dinucleotide dehydrogenase subunit 1 gene (nad1). Genomic DNAs were extracted from parasites isolated from individual host by sodium dodecyl sulfate-protease K treatment. The cox1 and nad1 genes were amplified by polymerase chain reaction and then sequenced and compared with that of other members of the Schistosomatidae available in GenBank, and phylogenetic relationships between them were re-constructed using the neighbor-joining method. The results showed that the lengths of cox1 and nad1 sequences were 1,125 and 518 bp, respectively, for all O. turkestanicum samples sequenced. The identities of cox1 sequences of O. turkestanicum from cattle, sheep, and cashmere goat in Daqing, China with that of O. turkestanicum from sheep in Iran were 99.4%, 99.7%, and 99.8%, respectively. The identities of nad1 sequences of O. turkestanicum from cattle, sheep, and cashmere goat in Daqing, China with that of O. cheni from cashmere goat at Fuyu, Heilongjiang Province, China were 99.4%, 99.0%, and 100%, respectively. Phylogenetic analyses based on the cox1 and nad1 sequences revealed that O. turkestanicum is placed within the African schistosomes, and O. turkestanicum should be considered the sister species of Schistosoma spp.