Analysis of genetic variability of Fasciola hepatica populations from different geographical locations by ISSR-PCR

摘要

Inter-simple sequence repeats markers were used to determinate the genetic variability of Fasciola hepatica populations recovered from sheep and cattle from Spain (Sp1, Sp2, Sp3 and Sp4), UK (Eng), Ireland (Ir) and Mexico (Mex). Twenty five primers were tested but only five produced 39 reproducible bands, being 7179% polymorphic bands. This percentage ranged from 1026% in Sp4 to 4872% in Sp1, and per host between 2821 and 4872% in sheep and between 1026 and 3846% in cattle. This relatively low range of genetic diversity within populations, with a mean of 3440%, implies that a large proportion of variation resided among populations. The population differentiation (Gst = 0547) indicated that 547% of variation is due to differences between populations and 453% due to differences within population. The Nei's distance ranged between 0091 and 0230 in sheep and between 0150 and 0337 in cattle. The genetic relationships between populations and individuals were shown by a UPGMA dendrogram and a principal coordinate analysis; both grouped all populations separately from Sp4, a population of from the Midwest of Spain with the lowest level of diversity. Small genetic distances were observed between Eng and Ir, on the one hand, and Sp1, Sp2, Sp3, from the Northwest of Spain, together with Mex, on the other.