Fig 1. Phylogenetic tree based on 16S rRNA data.

Sequences of the Scytonema hyalinum species cluster were generated using a combination of cloning strategy and PCR with specific primers designed for each of the two divergent operon types (for details see Materials and Methods). The clades corresponding to rRNA operon Type 1 and Type 2 are shown in shaded boxes. The operon Type 1 sequences form a long branch in the tree due to high dissimilarity to all available 16S rRNA sequences of cyanobacteria. Circles with numbers inside indicate strains in which both operon types were recovered. The tree is based on Bayesian Inference; branch supports ≥50% are given at the nodes in this shape: Bayesian Inference/Maximum Likelihood/Neighbor-Joining. Asterisks indicate nodes with ≥95% support from all methods.