COMPARISON OF THE 2ND INTERNAL TRANSCRIBED SPACER (RIBOSOMAL DNA) FROM POPULATIONS AND SPECIES OF FASCIOLIDAE (DIGENEA)

The nucleotide sequence of the 3' end of the second internal transcrib ed spacer region (ITS2) was determined for four isolates of Fasciola h epatica, two isolates of Fasciola gigantica, one isolate of Fascioloid es magna and one isolate of Fasciola sp. from Japan. Intraspecific seq uence divergence was negligible. Sequence divergence between F. hepati ca and F. gigantica was 2.8% and between Fasciola hepatica and Fasciol oides magna was 13.2%. The sequence of Fasciola sp. from Japan matched closely that of F. gigantica. This study demonstrates variability in nucleotide sequence within the ITS2 region which allows discrimination between species of Fasciolidae.