Single-cell RNAseq delineates the role of IRF7 in B cell differentiation through GC and PC fates. (A) Top 100 differentially expressed genes across the scRNAseq dataset were analyzed among all clusters. (B) Pseudotime analysis of the scRNAseq dataset projected using the UMAP to transcriptionally predict the differentiation projection of follicular B cells in FcγRIIB^−/− mice. (C and D) (C) Subclustering of the pre-GC transitional cluster (n = 2,461 cells) of splenic B cells from FcγRIIB^−/− mice using (D) markers associated with B cell differentiation into GC B cells. (E) Cell cycle analysis of cells in these subclusters. (F) The cells in subclusters were compared between FcγRIIB^−/− and FcγRIIB^−/−IRF7^−/− mice. (G) The percentages of cells in each subcluster from FcγRIIB^−/− and FcγRIIB^−/−IRF7^−/− mice that are in the cell cycle are shown in the bar graphs. LZ, light zone; DZ, dark zone.