STUDY BY RIBOSOMAL DNA ITS-2 SEQUENCING AND RAPD ANALYSIS ON THE SYSTEMATICS OF 4 METASTRONGYLUS SPECIES (NEMATODA, METASTRONGYLOIDEA)

Four species of lungworms of the Metastrongylus genus are found sympat rically in the lungs of the wild boars (Suss scrofa L.) on the Chambor d game reserve (France): Metastrongylus asymmetricus, M. confusus, M. pudendotectus, and M. salmi. These species are difficult to identify u sing morphological characters alone, and epidemiological evidence rais es doubt about the existence of 4 distinct species. Two molecular appr oaches (sequencing of ribosomal DNA Internal Transcribed Spacer 2 [ITS 2] and Random Amplified Polymorphic DNA assay [RAPD]) were used to ev aluate the genetic similarities between the 4 tars. The ITS 2 sequence s of M. salmi and M. confusus were identical, whereas the sequences of the other species were distinct. On the other hand, RAPD analysis ind icated unambiguously that the 4 species are genetically different. The se results reveal the limitation of using only 1 molecular approach fo r taxonomic studies and indicate the need to examine different regions (ribosomal, mitochondrial DNA) in the genome of a species in compleme nt with morphological and epidemiological data.