Figure 1

Microarray analysis of gene expression profiling in the Xpnpep1^−/− hippocampus. (a) Volcano plot showing the fold change and p value of the individual probe sets by microarray analysis. The vertical lines indicate 1.5-fold up-regulation (dotted red line) and down-regulation (dotted blue line), respectively. The horizontal dotted line represents the cutoff significance level (p = 0.05). The red and blue dots indicate up-regulated and down-regulated genes, respectively, with statistical significance. (b) The down-regulated genes in the Xpnpep1^−/− hippocampus are visualized by heatmap and hierarchical clustering. Each gene and sample were clustered by similarity between the expression patterns of genes. Red indicates high relative expression and blue indicates low relative expression. (c) Bar graphs represent average fold changes of down-regulated genes in the Xpnpep1^−/− hippocampus. (d,e) Treeview and hierarchical clustering (d) and average fold changes (e) of up-regulated genes in the Xpnpep1^−/− hippocampus. (b,d) Male: +/+1, +/+4, −/− 1, and −/−4; female: +/+2, +/+3, −/−2, and −/−3. (c,e) *p < 0.05; **p < 0.01; ***p < 0.001 by Student’s t-test, n = 4 pairs.