Agglomerative hierarchical clustering of blood and brain samples. (A) Hierarchical clustering of Fmr1-KO and wild-type samples. One hundred seven differentially expressed transcripts (nominal p-value < 0.01) are used for hierarchical clustering of transcripts (rows in the heatmap) and samples (columns in the heatmap). The gene expression levels are normalized across samples, and red (upregulated) and blue (downregulated) are color coded according to the bottom color bar. Color keys on the top of the heatmap denote tissue type and transgenic model. By far the most pronounced clustering is by tissue type. Within the blood samples, the two mice strains are clearly separated. (B) Hierarchical clustering of Tsc2 +/− and wild-type samples. One hundred fifteen significant transcripts are used for cluster analysis. Two mice strains formed separate clusters in each tissue type. The tissue specificity is not significant for the differentially expressed transcripts in Tsc2 +/− mice, whereas a majority of differentially expressed genes are highly expressed in cerebellum of Fmr1-KO mice (lower right cluster in the heatmap of Figure 1A).