FIG. 1.

Maximum-likelihood phylogeny of Blastocystis isolates inferred from SSU rRNA gene sequences. P. lacertae served as the outgroup. Bayesian posterior probabilities are given as percentages near the individual nodes. Nodes with values of <50% are not shown. Blastocystis isolates from humans are indicated in boldface. Groups I to VII are those previously described by Arisue et al. (7), and the arrows indicate isolates for which classification is uncertain. Scale bar, 0.1 substitutions (corrected) per base pair.