Fig. 4

Variable and invariable gene families involved in bacterial secretion separate by gene function. a Schematic diagram showing the type III (T3SS), type VI (T6SS), Sec, and Tat secretion system gene families measured in this dataset. Gene families are color-coded by whether they were variable (red), invariable (blue), or neither (gray), with strength of color corresponding to the FDR cutoff (color intensity). Insets show a summary of how many gene families in KEGG modules corresponding to a particular secretion system were variable or invariable and at what level of significance. b Heatmaps showing scaled residual log-RPKG for gene families (rows) involved in bacterial secretion. Variable (red) and invariable (blue) gene families were clustered separately, as were samples within a particular study (columns). log-RPKG values were scaled by the expected variance from the negative binomial null distribution. Genes in specific secretion systems are annotated with colored squares (T6SS: red-orange; T3SS: orange; Tat: yellow; Sec: grey)