DIFFERENCES IN THE 2ND INTERNAL TRANSCRIBED SPACER OF 4 SPECIES OF NEMATODIRUS (NEMATODA, MOLINEIDAE)

Genetic differences among Nematodirus spathiger, Nematodirus filicolli s, Nematodirus helvetianus and Nematodirus battus in the nucleotide se quence of the second internal transcribed spacer (ITS-2) of ribosomal DNA ranged from 3.9 to 24.7%. Pairwise comparisons of their ITS-2 sequ ences indicated that the most genetically similar species were N. spat higer and N. helvetianus. N. battus was the most genetically distinct species, with differences ranging from 22.8 to 24.7% with respect to t he other three species. Some of the nucleotide differences among speci es provided different endonuclease restriction sites that could be use d in restriction fragment length polymorphism studies, The ITS-2 seque nce data may prove useful in studies of the systematics of molineid ne matodes. (C) 1998 Australian Society for Parasitology. Published by El sevier Science Ltd.