Extended Data Fig. 4: Bulk sequencing validates single-cell atlas.

a–p, UMAPs highlighting distribution of cells from individual tissues in the steady-state fibroblast atlas. q, PCA of FACS-sorted bulk RNA-seq of fibroblasts and mesothelial cells, calculated for the 1,000 genes with the highest interquartile range. Circles represent fibroblasts and triangles are mesothelial cells. Each colour denotes a different tissue. r, Heatmap depicting top 20 Pi16⁺ (fibroblast) and Col15a1⁺ genes from steady-state fibroblast atlas in bulk RNA-seq data. Rows are z-scored. s, Gene enrichment analysis of top genes (log(fold change) > 0.5) from Pi16⁺ cluster and Col15a1⁺ cluster in loadings of PC1, which discriminates between mesothelial cells and fibroblasts (test: FGSEA, Benjamini–Hochberg correction). t, ATAC–seq traces of select genes from Pi16⁺ and Col15a1⁺ clusters genes, Ptprc (encoding CD45) and Hprt at ±2 kb of the TSS.