Figure 2

Phylogenic relationships of Diplogastridae based on concatenated SSU and ribosomal protein genes. The phylogenetic trees of 17 diplogastrid taxa were reconstructed from 5,996 bp of concatenated ribosomal protein CDS and SSU sequences. Coloured branches denote supported diplogastrid clades. Robustness of the tree topologies was evaluated by 1000 bootstrap replications. The support values are shown at the nodes. The trees were rooted by Rhabditoides inermis as outgroup. A. Maximum parsimony tree obtained by the heuristic search algorithm with the help of the PAUP*4.0b10 software [28]. Multistate characters were interpreted as polymorphisms, gaps as fifth state. B. Neighbour-joining tree. The tree was reconstructed using the BIONJ algorithm [42] and ML distances. C. Maximum likelihood tree. The codons were partitioned to three sites, corresponding to the GTR+SS model and the phylogenetic relationships were reconstructed by the heuristic search algorithm. D. Phylogenetic tree obtained by Bayesian inference using the Bayesian Estimation of Species Trees (BEST) software [35] applying gene partition. The analysis was run for 2,000,000 generations with a burnin of 500,000 generations. Tree sampling frequency was 1 in 100 generations. Numbers at nodes indicate posterior probabilities. The same tree topology was obtained using MrBayes 3.1.2 (Additional file 1) [29].