Characterization and identification of the Diophrys species (Protozoa, Ciliophora, Hypotrichida) based on RAPD fingerprinting and ARDRA riboprinting

Eight strains belonging to the three common Diophrys species were characterised using random amplified polymorphic DNA (RAPD) and amplified ribosomal DNA restriction analysis (ARDRA) methods with different random primers and restriction enzymes. The RAPD fingerprint patterns with three primers failed to reveal the intra- and inter-species relationships of members of Diophrys populations due to the low similarity indices (less than 46%) between different strains of the same species, which is out of the normal range of intra-species variation. However, ARDRA riboprinting successfully separated and identified D. oligothrix and D. appendiculata at the genetical level based on the patterns with Hinf I and Msp I enzymes. The patterns obtained with Hinf I were species-specific for all three species, but Msp I did not distinguish D. scutum from D. appendiculata . According to our molecular data, Diophrys populations present relatively high biological diversity, even between different strains of the same species. D. oligothrix and D. appendiculata are two morpho- and geno-species, which confirms that some morphological features, such as patterns of basal bodies in dorsal kineties and paroral membrane, are reliable for species identification and separation.