Microarray clustering and pathway analysis of heme-induced differentially expressed genes.

A. Hierarchical clustering of the microarray data showing that the diet-effect (C = control and H = heme) is more pronounced than the genotype-effect. B. Venn diagram showing that 69% of the heme-induced changes (q<0.01 and signal intensity>20 in at least one of the treatments) in WT mice could also be found in KO mice. Ingenuity canonical pathway analysis shows that overlapping genes in Venn-diagram are involved in cell cycle-related processes (open arrows) and Nrf2-mediated oxidative stress response (gray arrow). There is hardly any effect of genotype on fatty acid metabolism-related processes (black arrow). WT mice show PPARα activation (black arrow in WT panel) and KO mice Wnt signaling (white arrow in KO panel). Note that pathways in overlap are much more significant than the WT or KO specific pathways.