Research Paper Volume 6, Issue 7 pp 524—544

Figure 4. Transcriptional signature of aged skeletal muscle and its selected gene ontology terms of the mRNA transcriptome. (A) Unsupervised hierarchical clustering of the 136 differentially regulated mRNAs with aging; 123 genes were up-regulated, and 13 genes were down-regulated. Each column presents the mRNA expression in young (n = 5) and aged (n = 5) muscle. The intensity represents the magnitude of the difference. Red and green denote high and low expression, respectively. (B) Bar plot for the -log₁₀ of the P-value of the selected GO terms. The up- and down-regulated genes (2-fold change) were subjected to gene ontology analysis using DAVID. The enriched biological processes (upper) and molecular functions (lower) were plotted. White bar, enriched GO terms regulated by up-regulated genes; black bar, enriched GO terms regulated by down-regulated genes.