MP tree of 31 Blastocystis isolates and 3 outgroups based on SSU rDNA sequences. MP tree of 31 Blastocystis isolates (host in brackets) and 3 outgroups, based on SSU rDNA sequences. Bootstrap support values for four tree-reconstructing methods – ML, MP, LD and MD, respectively – are shown at the nodes. The symbol "+" is used for bootstrap support 99 and higher (in case only one "+" symbol is present, all methods scored such a high support). The effect of slow-fast analysis on nodes is represented by arrow symbols in the figure. Increase of an average bootstrap support by more than 10% of one and more than one tree-reconstructing method in two datasets (BlastS3 and S2) is marked with "↑" and "↑↑", respectively. Similarly, the decrease of bootstrap support is marked with "↓" and "↓↓" at the particular nodes. Bootstraps of other nodes did not change dramatically. Except for our five new isolates (GERA3A, GERA3B, GEPA2, GECA2, KINIX2), Blastocystis isolates are labeled with accession numbers of their SSU rRNA gene sequences.