De novo developed microsatellite markers in gill parasites of the genus
Dactylogyrus (Monogenea): revealing the phylogeographic pattern of
population structure in the generalist parasite Dactylogyrus vistulae
Abstract
Approaches using microsatellite markers are considered the gold standard
for modern population-genetic studies. However, though they have found
application in research into various platyhelminth taxa, they remained
substantially underutilized in the study of monogeneans. In the present
study, a newly-developed set of 24 microsatellite markers was used to
investigate the genetic diversity of the generalist monogenean species
D. vistulae. The analyzed parasite specimens were collected from 13
cyprinoid species from 11 sites in the Apennine and Balkan peninsulas. A
total of 159 specimens were genotyped at each of the loci and the number
of alleles per locus ranged from 2 to 16, with a mean number of 6.958
alleles per locus. Exceptionally high genetic diversity was observed
among D. vistulae individuals in the southern Balkans, suggesting that
this region might represent the center of diversification of the genus
in Europe, from where Dactylogyrus parasites expanded into the north.
The initial clustering analysis divided all investigated specimens into
three major clusters; however, the results of the subsequent analyses
revealed the existence of various subpopulations, suggesting that the
population structure of D. vistulae is associated with the
diversification of their cyprinoid hosts. In addition, partition of the
parasite population was observed in regions of the sympatric occurrence
of two host species, indicating that these hosts may represent a barrier
to gene flow, even for generalist parasite species.