Impact of temporal changes and host factors on the genetic structure of a population ofOpisthorchis viverrini sensu latoin Khon Kaen Province (Thailand)

Abstract

SUMMARYThe population genetics of 317 individualOpisthorchis viverrinifrom Khon Kaen Province Thailand, from 4 different years and 4 cyprinid fish species was examined using multilocus enzyme electrophoresis of enolase (Enol), phosphoglucomutase (Pgm) and triose phosphate isomerase (Tpi). Allele and genotype frequencies forEnolandPgmwere consistent irrespective of year or host species. No heterozygote deficiency was detected forEnol. Significant heterozygote deficiencies were detected in 3 of 4 years forPgm. ForTpi, allele frequencies of the most common allele and genotype frequency varied between years and among individuals from different host species. Heterozygote deficiencies forTpiwere detected in 2 years. No significant heterozygous deficiencies were detected amongO. virerrinifrom different fish species in 2005, except atPgmandTpifromPuntioplites protozsron. There was no statistical significance in pairwiseFSTvalues betweenO. viverrinifromCyclocheilichthys armatusin different years or different host species in 2005. Significant departures from Hardy-Weinberg expectations and a high rate of gene flow in a population ofO. viverriniare discussed in terms of self- and cross-fertilisation, natural selection, non-random mating, the Wahlund effect, presence of null alleles, intensity of infection, biology and ecology of their intermediate cyprinid hosts.