Fig. 1.

Maximum likelihood (ML) phylogeny inferred from the 310 concatenated gene sequences shared by Buchnera strains and E. coli (Eco). The support values for the corresponding inner branch are 100/1.0 in the form of the proportion of bootstrap pseudoreplicates/Bayesian a posteriori probabilities, respectively. The total numbers of genes of each strain, as well as in the last common symbiotic ancestor (LCSA), are indicated in gray boxes. Numbers within squares at the nodes indicate the total number of gene losses. B. aphidicola strain abbreviations are as explained in Table 1, footnote b.