Genetic variation and genome organization of VA genes ordered along the PtoDC3000 chromosome. The percentage of variation for each VA gene is plotted according to the genome location of its PtoDC3000 ortholog. The x-axis shows the genome location in megabases; the y-axis shows the variation among strains (0%, no variation and present in all strains). Triangles, effectors; circles, hrp/hrc genes; ×, all other VA genes. T3SS, fla, yer, gsp, and cor approximate locations of the genes encoding T3SS apparatus, flagella apparatus, yersiniabactin biosynthesis, general secretory pathway, and coronatine biosynthesis. pA and pB represent the two endogenous plasmids of PtoDC3000.