Genetic Variability of Echinococcus granulosus Determined by the Mitochondrial Cytochrome c Oxidase Subunit 1 Gene in the Tibet Plateau of China

The genetic variability of Echinococcus granulosus was investigated to uncover the genetic structure in the Tibet plateau,China.The complete mitochondrial cox1 genes about 1 609 bp from 47 isolates of E.granulosus collected from populations in the Tibet plateau were sequenced.Further sequences(retrieved from NCBI database)for the cox1 gene from the Tibet plateau and the Middle East were compared with the sequences analyzed in this study.The BLAST analysis of the sequences indicated 47 isolates belonged to G1genetype(E.granulosus sensu stricto)and 10haplotypes(C1-C10)were detected.The major haplotype C1 in the Tibet plateau showed a 100%homology with the reference haplotype in the Middle East and presented a worldwide distribution.The haplotype diversity(Hd)and nucleotide diversity(π)observed in the Tibet plateau were both lower than these in Middle East.The average negative values of Tajima's Dand Fu's Fs were negative in the two geographic populations and the populations were not genetically differentiated.These results suggest that E.granulosusin the Tibet plateau occurred demographic expansion or bottleneck effects after the introduction of founder haplotype in the Middle East.The population was developed under the geographical isolation.