Fig 4. Phylogenetic tree.

Maximum Likelihood tree displaying the phylogenetic relationships between the Cladonema sp. ectosymbiont (in bold) with other endo and ectosymbionts sulphur-oxidizing bacteria based on the analysis of 16S rRNA gene sequences of 926 nucleotides. Methylocystis parvus was used as the outgroup. Only bootstrap values of more than 50% are shown at each node. The white circles with or without black dot indicate whether symbionts are intra- or extracellular respectively. The scale bar corresponds to 0.02 changes per nucleotide.