Fig. 1

Frequencies of bacteria at different taxonomic levels in unfractionated RNA samples from the propleural plates of ants provided with a 20% (w/v) solution of either ¹²C- or ¹³C-labelled glucose. A Phylum resolution, showing that > 75% were Actinobacteria. The remaining reads almost all corresponded to Wolbachia (Proteobacteria) so the three other phyla do not appear in the bars (total relative abundance of 0.6% and 0.4% in ¹²C and ¹³C fractions, respectively). As Wolbachia is not part of the cuticular microbiome (see text), these results show that the cuticular microbiome is completely dominated by Actinobacteria. B Genus-level resolution showing that the cuticular microbiomes are dominated by the native Pseudonocardia symbiont followed by appreciable fractions of horizontally acquired Streptomyces species and a series of other Actinobacteria at low prevalence