Genetic diversity of the Chinese liver fluke Clonorchis sinensis from Russia and Vietnam

- Low nucleotide and high haplotype differentiation was revealed in Russian and Vietnamese samples of Clonorchis sinensis.
- A clear northward direction was detected for haplotype frequencies and pattern of nucleotide diversity along the cox1 gene.
- There are several region-specific phylogenetic lineages which could have occurred in the penultimate Pleistocene glaciation.
- The results suggest a deep local adaptation of the fluke and population growth with no bottleneck in the late Pleistocene.
- The data promote understanding of species phylogeography, parasite-host interactions and epidemiology of clonorchiasis.