Maximum Likelihood phylogenetic tree derived from amino sequences of DBD and LBD. The phylogenetic relationship among TRs was examined by the Maximum Likelihood method (ML) and Bayesian inference with the same methods as in Fig. 6. Support values for ML tree were obtained by bootstrapping a 100 replicates and are indicated above each branch. Branches under the bootstrap value of 50 were shown as polytomies. Bayesian inference was running 3 million generations. The PPs are shown below each branch or after the ML bootstrapping value separated by a slash. Star indicates the node obtained form by Bayesian inference which was different from that obtained by the ML method. SmTRα: blood fluke S. mansoni TR alpha, SmTRβ: S. mansoni TR beta. The accession number of each sequence used for phylogenetic analysis can be found in Additional files 1 and 2.