SPECIES DIFFERENTIATION OF LUNGWORMS (DICTYOCAULIDAE) BY POLYMERASE CHAIN REACTION RESTRICTION-FRAGMENT-LENGTH POLYMORPHISM OF 2ND INTERNALTRANSCRIBED SPACERS OF RIBOSOMAL DNA/

The bovine lungworm Dictyocaulus viviparus is found in cattle and deer species (roe deer, fallow deer). Although a separate lungworm species (D. eckerti) from roe deer has been described, this description, base d on minor morphological differences, is not generally accepted. The a im of the present study was to examine genetic differences among four lungworm species isolated from cattle, sheep, horses, and fallow deer. Ribosomal second internal transcribed spacers (ITS2) of individual wo rms of all species were amplified by polymerase chain reaction (PCR), and restriction-fragment-length polymorphisms were analyzed after dige stion with five different restriction enzymes. After electrophoretic s eparation of the digested PCR products, all four lungworm species show ed different banding patterns. Lungworms from cattle (D. viviparus) an d those from fallow deer (D. eckerti) were genetically distinct. These results are consistent with the hypothesis that the taxonomic classif ication of D. eckerti as a separate species is correct.