Figure 3

Gene expression similarities of differentially regulated genes in WT and Ercc1^-/Δglomeruli. (A) Hierarchical clustering of 257 genes differentially expressed in WT mice of 96 wks compared to WT 14 wks only. Glomerular genes differentially expressed in early mouse life between 4 and 14 weeks of age were considered to play a role in glomerular maturation and not in aging processes and thus were excluded from the dataset. This subset of genes mapped to aged WT mice (black), aged Ercc1^-/Δmice (dark green), 14 wks old WT mice (grey) and young Ercc1^-/Δmice (light green) is shown. Young WT samples share a subcluster with young Ercc1^-/Δsamples, aged WT as well as Ercc1^-/Δsamples show a distinct cluster. Upregulated genes are shown in orange, downregulated genes are displayed in yellow. (B) Hierarchical clustering of all 448 genes differentially regulated in WT mice of 96 wks compared to WT 14 wks as well as in Ercc1^-/Δmice of 14 wks compared to 4 wks. Prior to hierarchical clustering, glomerular genes differentially regulated in early mouse life between 4 and 14 weeks of age were subtracted from the dataset. Old wild-type mice (black) and old Ercc1^-/Δmice (dark green) shared a distinct subcluster. Furthermore, young wild-type mice (grey) and young Ercc1^-/Δmice (light green) share another distinct subcluster, reflecting the similarity of the sets of differentially regulated genes between WT and Ercc1^-/Δglomeruli in young as well as in old tissue. Upregulated genes are shown in orange, downregulated genes are displayed in yellow.