Fig. 4

Co-expression network analysis of aging-related transcriptomic profiles. a Visual network constructed using the top 5000 connections of each network from four organs. Edge colors represent different organs. b Bar chart illustrating the numbers of connections and nodes across the four organs. The matrix of solid and empty circles at the left illustrates the “presence” (solid red) or “absence” (empty) of the organ in each intersection. The bar at the right represents the percentage of connections and nodes in each intersection. The total percentages of connections and nodes that are shared by at least three organs, two organs, and unique to a single organ are shown on the right. c Heatmap of eigengenes from selected aging-biased modules and corresponding enriched GO and KEGG terms in each organ. The left panel is the heatmap of module eigengenes associated with age status. The names and number of genes (shown in parentheses) of modules are listed on the left. The high and low eigengene values of each module are marked in red and blue, respectively. The right panel is the grid of enriched GO and KEGG terms in modules, and red boxes represent modules with significant enrichment (GO terms with P < 0.01 and KEGG terms with P < 0.05). The color density represents the corresponding P-value (a deeper red color indicates a more significant term)