Hierarchical clustering of significantly regulated genes. We performed hierarchical clustering analysis on the 302 significantly, differentially expressed transcripts (FDR<0.01) similarly regulated in Colony 1 (A) and Colony 2 (B). Both colonies demonstrated the same overall grouping for experimental treatments: saline (S) and bead (B) injected bees formed a sister group and were closer in transcript expression to bacteria (Bac) injected bees than controls (C). Control and bacteria-injected bees had the most disparate transcript expression. Colours denote differences in log2 expression relative to the mean expression across the four treatment groups, according to the scale shown.