Phylogenetic trees of the 16S rRNA gene (A) and MLSA (B) based on maximum likelihood method. Distance estimation was obtained by the model of Kimura 2-Parameter. Bootstrap percentages after 2,000 replications are shown. Scale bar, estimated sequence divergence. Synechococcus elongates PCC6301 was used as an outgroup. MLSA tree: new Prochlorococcus species (T type strains), MLSA (%), AAI (%), GGD (%) and Genome Signature (GS) values for each Prochlorococcus pair, location and depth are indicated on the right side of the tree. This figure is reproduced with permission from Thompson et al. .