Purpose: The giant liver fluke, Fascioloides magna, is an important parasite of white-tailed deer (Odocoileus virginanus), a commercially important game species in the northeastern United States. However, the parasite has never been genetically characterized from this region and so its genetic interrelationships with other enzootic populations on the continent are unknown. The purpose of this study was to genetically characterize F. magna from the Adirondack region of northern New York (NNY) and determine its relationship with its enzootic cohorts.
Methods: Flukes were extracted from seven livers of O. virginanus at three localities in and around the Adirondack Park in northern New York. DNA was extracted from eight individuals using standard procedures, and a 440-bp fragment of the COI gene was amplified using species-specific primers. F. magna sequences generated from a previous phylogeographic study were obtained from the GenBank database and a mtDNA dataset was compiled, aligned, and edited for molecular analyses. Analyses based on eight mtDNA sequences included haplotype network reconstruction, along with hierarchical and pairwise (ФST) AMOVA tests.
Results: F. magna from the Adirondacks was found to be most genetically similar to specimens from Minnesota based on shared haplotypes and relatively low genetic differentiation (ФST = 0.331). East coast enzootic populations exhibited panmixia while their west coast cohorts were genetically distinct.
Conclusion: Based on the strong genetic similarities between F. magna from northern New York and Minnesota, we propose that the GLR enzootic range of F. magna be extended to encompass the Adirondack region of NNY.
Keywords: Cox1; Deer; Parasite; Phylogeography.