AN ALTERNATIVE APPROACH TO EVALUATING THE INTRASPECIFIC GENETIC-VARIABILITY OF PARASITES

Analysis of DNA polymorphisms provides important information for the m olecular characterization of parasite strains and clones. Because we s till know little about the genomes of parasites, such analysis has to rely on methods applicable to any eukaryotic genome, such as DNA finge rprinting with multilocal minisatellite probes and the polymerase chai n reaction (PCR)-based random amplified polymorphic DNA technique (RAP D). However, DNA fingerprinting is cumbersome and needs large amounts of parasite DNA, and RAPD can exhibit low reproducibility and spurious bands, both of which appear to be related to the low stringency of th e PCR procedure. Riva Oliveira, Andrea Macedo, Egler Chiari and Sergio Pena here evaluate the applicability to parasites of a technique desc ribed two years ago called simple sequence repeat-anchored PCR amplifi cation (SSR-PCR), in which a single primer is needed [the (CA)(8)RY pr imer] and high-stringency conditions are applied.