The super repertoire of type IV effectors in the pangenome of Ehrlichia spp. provides insights into host-specificity and pathogenesis
Fig 5
The distribution of Ehrlichia type IV effectomes according to local gene density shows an enrichment of pT4Es in gene sparse regions.
Distribution of E. canis str. Jake genes according to the length of their flanking intergenic regions (FIRs). All E. canis genes were sorted in two-dimensional bins according to the length of their 5′ (y-axis) and 3′ (x-axis) FIRs. The number of genes in the bins is represented by a colour-coded density graph. Genes whose FIRs were both longer than the median length of FIRs were considered as gene-sparse region (GSR) genes. Genes whose FIRs were both below the median value were considered as gene-dense region (GDR) genes. In between region (IBR) genes are genes with a long 5′ FIR and short 3′ FIR, and inversely. For E. canis, this median value is 225 bp for 5′ FIRs and 304 bp for 3′ FIRs. The dashed line showing the median length of FIR delimits the genes in GSR, GDR and IBR. Candidate effectors predicted using the S4TE 2.0 algorithm were s plotted on this distribution according to their own 3′ and 5′ FIRs. A colour was assigned to each of the three following groups: red to GDRs, orange to IBRs, and blue to GSRs. Specific pT4Es are represented by a dot circled in black. In the top right corner, a Circos graph shows the distribution of E. canis str. Jake putative effectors along the genome. The outermost and second circles (in grey) represent E. canis antisense and sense genes, respectively. The third and innermost circles represent pT4Es. The black, red, orange and blue colour of each putative T4 effector corresponds to species-specific effectors located in GDRs, IBRs and GSRs, respectively.