Phylogenetic relationships of GRs, TRs and TGRs of platyhelminths and mammals. TRs, GRs and TGRs from platyhelminths and mammals were aligned with Clustal W2 . Human dihydrolipoamide dehydrogenase (DLDH) was used as outgroup. A Neighbor-Joining tree was constructed using MEGA4  with pairwise deletion and default parameters. A condensed tree is shown, and bootstrap values of reliable nodes (above 50) are indicated. The polytomy displayed at the TGR node denotes that the evolutionary relationships within the node can not be resolved with at least 50% of bootstrap support. In other words, nodes with less than 50% of bootstrap support were collapsed and are displayed as polytomies. The results indicate that the TR and GR genes present in the planarian lineage were lost in the neodermata lineage. Very similar topology and statistical support were obtained using different phylogenetic reconstruction methods (i.e. Maximum Parsimony, UPMGA and Minimum Evolution). ECHGR: E. granulosus, ECHMU: E. multilocularis, TAESO: T. Solium, SCHMA: S. mansoni, SCHJA: S. japonicum, SMED: S. mediterranea, FASHE: F. hepatica.