[Polymorphism of the coxl mtDNA gene from cercarian isolates of the avian schistosome Bilharziella polonica (Trematoda: Schistosomatidae) from Belarussian lakes].

We have studied the phylogeographic structure of avian schistosomes Bilharziella polonica (class Trematoda, family Schistosomatidae), parasites of 18 molluscs Planorbius 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 (coxl) was found on the part of the species range studied. The phylogeographic reconstructions showed that the sample examined consists of at least two lineages ofhaplotypes 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 180,000-270,000 years. Possible evolutionary scenarios for differentiation of the B. polonica lines and effectiveness of using coxl for barcoding trematode populations and finding coevolutionary parasite-host relationships are discussed.