Polymorphism of the cox1 mtDNA Gene from Cercarial Isolates of the Avian Schistosome Bilharziella polonica (Trematoda: Schistosomatidae) from Belarussian Lakes

We have studied the phylogeographic structure of avian schistosomes Bilharziella polonica (Trematoda: Schistosomatidae), parasites of 18 molluscs Planorbarius corneus (family Planorbidae) from three Belarussian lakes. Low nucleotide (pi < 0.5%) and high haplotype (h = 85.6%) diversity of the gene encoding the cytochrome C oxidase first subunit (cox1) was found on the part of the species range studied. The phylogenetic reconstructions showed that the sample examined consists of at least two lineages of haplotypes, A and C. Haplotype diversity was somewhat higher in lineage C. The genetic divergence between these genealogical lines reached 0.55%, while the time of possible divergence was 180000-270000 years. Possible evolutionary scenarios for differentiation of the B. polonica lines and effectiveness of using cox1 for barcoding trematode populations and finding coevolutionary parasite-host relationships are discussed.