Genetic variability of the main intermediate host of the Schistosoma mansoni in Brazil, Biomphalaria glabrata (Gastropoda: Planorbidae) assessed by SSR–PCR

The genetic variability of Brazilian Biomphalaria glabrata populations was studied using SSR–PCR. This technique is a variant of the polymerase chain reaction (PCR), which consists of using a single primer directed towards microsatellite regions under high stringency reaction conditions. Twenty snails of each population from eight distant Brazilian localities were analyzed. Morphology and PCR–RFLP were used for previous specific identification of the snails. Bands generated after gel electrophoresis of the SSR–PCR products of each snail were used to study intra- and interpopulation genetic variability. Fifty-five prominent bands were considered in a pairwise band comparison for the determination of genetic variability. Genetic variability was greater between populations than within populations. Snail populations from the field and the laboratory presented almost no genetic differences. No relationship between genetic variability and geographic distance was found. SSR–PCR proved to be a good alternative molecular tool for the population study of B. glabrata.