(A) Hierarchical clustering analysis of differentially expressed genes in hearts from Lmna^+/+, Lmna^H222P/+, and Lmna^H222P/H222P mice. Rows indicate the individual genes expressed and columns indicate each sample. A color is assigned to each gene depending on its expression (red indicates higher expression and green indicates lower expression). Transcriptional profiles of hearts of Lmna^H222P/H222P and Lmna^H222P/+ mice show a greater degree of similarity to each other than to hearts of control Lmna^+/+ mice. (B) Volcano plots of absolute expression values (log₂[q value]) determined by robust multichip analysis. For each probe set, expression in hearts from Lmna^H222P/H222P and Lmna^H222P/+ mice is plotted. A 2-fold threshold and q < 0.05 were used to determine the probe sets significantly altered in the analysis (red). (C) Validation of RNA expression profiling of selected genes in hearts from Lmna^+/+, Lmna^H222P/+, and Lmna^H222P/H222P mice using real-time PCR. Bars indicate the fold overexpression of the indicated mRNA in hearts as calculated by the ΔδC_T method. Values are mean ± SD for n = 6 samples per group. Real-time PCR was performed in triplicate with the different RNA samples. Matrices visualizing Affymetrix GeneChip data of corresponding probe sets of RNAs are shown at right of bar graph. In these matrices, each probe set is visualized as a row of colored squares with 1 square for each sample. Myh7, Myh4, Myl7, Acta2, and Sln show higher expression (red) and Pttg lower expression (green) compared with controls.