Isolation, characterization and population-genetic analysis of microsatellite loci in the freshwater snail <i>Galba cubensis</i> (Lymnaeidae)

Abstract

The freshwater snail <i>Galba cubensis</i> (Pfeiffer, 1839) has a large distribution in the Americas. Despite being an intermediate host of <i>Fasciola hepatica</i> - the trematode causing fasciolosis in livestock and humans - its population genetics have never been studied. We isolated and characterized 15 microsatellite loci in <i>G. cubensis</i> to evaluate its genetic diversity, population-genetic structure and mating system. We tested the microsatellite loci in 359 individuals from 13 populations of <i>G. cubensis</i> from Cuba, Guadeloupe, Martinique, Puerto Rico, Venezuela, Colombia and Ecuador. We also tested cross-amplification in three closely related species: <i>G. truncatula</i>, <i>G. viator</i> and <i>G. neotropica</i>. We found that <i>G. cubensis</i> has a similar population structure to other selfing lymnaeids that live in temporary habitats: low genetic diversity, large departure from Hardy-Weinberg equilibrium, marked population structure and high selfing rate. We found that seven and six loci amplified in <i>G. truncatula</i> and <i>G. viator</i>, respectively, and that all 15 loci amplified in <i>G. neotropica</i>. This last finding suggests a close relatedness between <i>G. cubensis</i> and <i>G. neotropica</i>, probably being conspecific and synonymous. This new set of microsatellite markers will be a useful tool to study the genetic diversity of this snail species across a large geographical range and, consequently, to understand the emergence and re-emergence of fasciolosis in the Americas.