Figure 2.

Example phylogenetic tree considered to support a hypothesis of HGT involving PVC organisms. Tree is adapted based on Figure 5b of an analysis of sterol synthesis by Pearson et al. (2003). The tree was drawn using all bacterial oxidosqualene cyclase (OSC)-family sequences available in the public databases at the time of the analysis. Taxon labels indicate the genus from which the sequence was sampled. The “MetylSHC” label indicates a sequence taken from the bacterium Methylococcus capsulatus, and is a member of the squalene–hopene cyclase (SHC) gene family, which is related to the OSC family. All eukaryotic sequences are labeled in red, all non-PVC bacterial sequences are labeled in blue, the one PVC sequence is labeled in light blue with a dark blue background. The branch that partitions all eukaryotic sequences from all bacterial sequences is drawn thicker than all other branches in the tree.