CHARACTERIZATION OF DNA RESTRICTION PROFILES AND RIBOSOMAL-RNA GENE RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS OF PROTEOCEPHALUS-EXIGUUS ANDP-NEGLECTUS FROM GEOGRAPHICALLY DISTINCT REGIONS

The total DNA of two morphologically similar cestode species of the ge nus Proteocephalus parasitizing coregonid and salmonid fish, P. exiguu s La Rue, 1911 and P. neglectus La Rue, 1911, was compared. The method s of DNA analysis involved digestion of the total DNA with restriction endonucleases and Southern blotting hybridization with the ribosomal DNA probes pSM 889, pSM 389 and pSM 890. No inter-specific variation w as found between the two proteocephalid species. Distinct differences in RFLP patterns were recorded between two geographically distinct pop ulation of P. neglectus after BspRI digestion; after EcoRI digestion a nd following hybridization with the P-32-labelled probe pSM 890 and af ter BamHI digestion and hybridization with the P-32-labelled probe pSM 889. The high degree of genetic similarity revealed in the two Proteo cephalus spp. could be a further argument for the conspecifity of both taxa.