Fig. 1

scRNA-seq analysis of peritoneal B cells in neonatal, young, and elderly mice. a Experimental design for scRNA-seq and scBCR-seq analysis of peritoneal B cells (created with BioRender). b A Uniform Manifold Approximation and Projection (UMAP) visualization of scRNA-seq data of all examined peritoneal CD19⁺ cells. Cells were purified from neonates (day 5, pool of 10 pups from 1 litter; day 6, pool of 7 pups from 1 litter), young adults (week 10, n = 1; week 11, n = 2), and elderly (month 15, n = 1 and month 19, n = 1) of wildtype C57BL/6 mice. c−e Distribution of gene expression in UMAP plots. The color key indicates the expression level. f Distribution of B1 cells, B2 cells, and B cell precursors in the UMAP plot. g The pie charts show the percentages of peritoneal B1 cells, B2 cells, and B cell precursors in different ages. h The heatmap shows the expression patterns of indicated genes in B1 cells, B2 cells, and B cell precursors. The color key indicates the expression level. PerC, peritoneal cavity. MACS, magnetic-activated cell sorting