Figure 1. Maximum likelihood phylogenetic analyses of parabasalids based on GAPDH (A), actin (B), and EF-1α (C) sequences.

Unambiguously aligned protein sequences of 278 (A), 280 (B) and 274 (C) sites were used for phylogenetic inference. The species names of the parabasalids except for the genus Trichonympha are shown in Table 1. The GAPDH sequences of Trichonympha acuta and Eucomonympha imla and the EF-1α sequence of Trichomonas tenax (not shown in Table 1) were also included in the analyses. Although the EF-1α sequences published for Pentatrichomonas and Tritrichomonas [57] were not included in C because of their shorter sequence length, the analysis with a reducing number of sites (219 sites) demonstrated that they were related very closely to the sequences from the same taxa shown in C. The sequence accession number was indicated for each taxon. The sequences used for the concatenation are in bold. The trees were estimated in RAxML and the numbers near the nodes indicate the bootstrap values. Values below 50% are not shown. Vertical bars to the right of the trees represent the parabasalian classes according to [26]: C, Cristamonadea; S, Spirotrichonymphea; Tn, Trichonymphea; Tt, Tritrichomonadea; H, Hypotrichomonadea; and Tm, Trichomonadea. Scale bars correspond to 0.10 substitutions per site.