Genetic variability in Brazilian populations of Biomphalaria straminea complex detected by simple sequence repeat anchored polymerase chain reaction amplification

Biomphalaria glabrata, B. tenagophila and B. straminea are intermediate hos ts of Schistosoma mansoni, in Brazil. The latter is of epidemiological impo rtance in the northwest of Brazil and, due to morphological similarities, h as been grouped with B. intermedia and B. kuhniana in a complex named B. st raminea In the current work, we have standardized the simple sequence repea t anchored polymerase chain reaction (SSR-PCR) technique, using the primers (CA)(8)RY and K7, to study the genetic variability of these species. The s imilarity level was calculated using the Dice coefficient and genetic dista nce using the Nei and Li coefficient. The trees were obtained by the UPGMA and neighbor-joining methods. We have observed that the most related indivi duals belong to the same species and locality and that individuals from dif ferent localities, but of the same species, present clear heterogeneity. Th e bees generated using both methods showed similar topologies. The SSR-PCR technique was shown to be very efficient in intrapopulational and intraspec ific studies of the B. straminea complex snails.