Figure 4. Cell-type-specific changes in molecular signatures across ages.
(A) Number of differentially expressed (DE) genes between juvenile and old animals in individual cell clusters, with genes up- and downregulated with age shown in red and blue bars, respectively. DE genes were defined as genes with age-related change in log(gene expression) > 2 (light colored bars) or >2.5 (dark colored bars) and FDR-adjusted p-value < 0.05 between the two ages.
(B) Age-related change in Z-scored log(gene expression) between juvenile and old animals for DE genes in different cell clusters.
(C) −log10(p-value) of enrichment for gene ontology (GO) biological process terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms enriched among DE genes with an age-related change in log(gene expression) > 2 and FDR-adjusted p-value < 0.05 between the two ages (juvenile and old). Only top 10 (or fewer) GO or KEGG terms with p-value < 0.05 are listed for each major cell class.
(D) Spatial maps of examples of DE genes across the three different ages, showing the expression of each gene within the indicated cell type. Gray spots indicate all other cells of other types.. Scale bar: 500 μm.
(E) Quantification of the number of DE genes for each major cell type as a function of spatial location using imputed gene expression data derived from Harmony integration. DE genes with an age-related change in log(gene expression) > 2 and FDR-adjusted p-values < 0.05 are considered. Size of dot indicates total number of DE genes for a particular cell type within a region, and color shade of dot indicates the fraction within a particular region of the total number of DE genes that are differentially expressed across all regions, plotted on a relative scale of minimum fraction to maximum fraction across all regions.
See also Figures S2 and S4 and Tables S1–S3.