Indexed on: 01 Mar '97Published on: 01 Mar '97Published in: Systematic Parasitology
The 'hypervariable' region of the 18S ribosomal DNA gene, comprising 344 base pairs, was sequenced for five species of the genus Schistosoma (S. intercalatum, S. margrebowiei, S. mattheei, S. malayensis and S. rodhaini), representing three of the schistosome species groups. Heterobilharzia americana was also included as an outgroup. The sequences were compared with previously published sequences (S. haematobium, S. japonicum, S. mansoni and S. spindale). The analysis confirmed that the Asian schistosomes were distantly related to the other groups of schistosomes and showed that the amount of variation within the S. japonicum group (1.49%) was greater than that detected within the S. mansoni and S. haematobium groups (0% in each case).