Fig. 7

Endosymbionts and other intracellular species have generally weak ∆LFE. a Comparison of ∆LFE values at different CDS positions between endosymbionts (green) and other species (pink). The ∆LFE values are less extreme in endosymbionts, indicating lower selection on local folding strength. b Comparison of ∆LFE distributions at different CDS positions between endosymbionts (green) and other species (pink) within gammaproteobacteria (N = 44). c ∆LFE for species included in the tree within gammaproteobacteria; the endosymbionts and intracellular species (marked) have weaker ∆LFE bias compared to their relatives. d PCA plot for ∆LFE profiles (left, see “Visualization” under the “Methods” section) and the intracellular classification (right) for the species in gammaproteobacteria (N = 44). For clarity, overlapping profiles are hidden on the left (as in all PCA plots for ∆LFE profiles); all species are plotted on the right. Short species names in the PCA plot on the left panel are listed in Additional file 1: Table S3