Evolutionary relationships between Opisthorchis viverrini and related platyhelminths based on similarities of protein coding genes using SimiTri. Similarity of O. viverrini ORFs (1,932 ESTs) to those from the liver fluke Clonorchis sinensis (2,679 ESTs), the blood fluke Schistosoma japonicum (107, 427 ESTs) and the free-living turbellarian Schmidtea mediterranea (171,472 ESTs). SimiTri  was used to plot 1,932 O. viverrini contigs against related species database entries (A). Each spot represents a unique contig and its sequence similarity to each of the three selected databases as determined by tBLASTx scores. Sequences showing similarity to only one database are not shown. Sequences showing sequence similarity to only two databases appear on the lines joining the two databases. Spots are coloured by their highest tBLASTx score to each of the databases. O. viverrini sequences with homologues in the parasitic flukes only (not in Schmidtea) are highlighted in the dotted region and the identities of selected examples are shown in the table (B). The entire list (105) of these putative parasite-specific proteins is shown in Table S1.