Figure 1

Molecular phylogeny of chemosynthetic symbionts based on 16S rRNA gene sequences. These uncultured symbiont taxa are represented by their hosts' scientific name and symbionts, where named, are included in parentheses. A Maximum Likelihood analysis (GTR + gamma) was used with 1,000 bootstrap replicates. Bootstrap values greater than 50% are shown at nodes. Sequenced bacterial genomes in this analysis are boxed while those included in heterologous microarray analyses are circled. Thiomicrospira crunogena, a free-living chemoautotroph used as a point of reference for the genomic comparisons, is also highlighted. V = Vesicomya; C = Calyptogena; E = Ectenagena.