Figure 1

Distribution of ISRpe1 along the 16S rRNA phylogeny of bacterial endosymbionts. (A) Wolbachia phylogeny; (B) Rickettsia phylogeny; and (C) Bacteroidetes phylogeny. The left part of the figure shows the phylogeny of the Wolbachia (α-proteobacteria), Rickettsia (α-proteobacteria), Cardinium (Bacteroidetes) and Amoebophilus (Bacteroidetes) strains via maximum likelihood. Bacterial strains are here identified either by their names (if any) or by the prefix S followed by the proper name of their host. Numbers on branches indicate percentage bootstrap support for major branches (1000 replicates; only bootstrap values of 60% or more are shown). Bacterial strains harboring ISRpe1 are shown in bold. The scale bar is in units of substitutions per site. The right part of the figure gives the distribution of ISRpe1 observed with each bacterial strain (black: potentially functional ISRpe1 copies, n=62; white: non-functional copies, n=67; gray: unknown functional status, n=26). Methods of detection are indicated by letters (a: specific PCR assays; b: full genome sequencing).