Single-cell RNAseq identifies 14 clusters in SLE-prone FcγRIIB ^−/− B cells. (A) Gating strategy for sorting 90% IgD⁻ activated and 10% IgD⁺ naïve B cells for scRNAseq analysis. Panel A is duplicated in Fig. S5. (B) Unsupervised clustering of 36,842 splenic B cells from 3-mo-old FcγRIIB^−/− and FcγRIIB^−/−IRF7^−/− mice, visualized using UMAP. Cells analyzed contained 10% B220⁺IgD⁺ naïve and 90% B220⁺IgD⁻ activated B cells that were sorted from two individual FcγRIIB^−/− and FcγRIIB^−/−IRF7^−/− mice (n = 4 mice). (C) Representative UMAPs of hallmark genes to demonstrate annotation of populations in the scRNAseq dataset. Gene expression for clusters is shown at a log scale. (D) UMAPs depicting the distribution of cells between the FcγRIIB^−/− and FcγRIIB^−/−IRF7^−/− mice. (E) The percentage of cells in each B cell cluster from FcγRIIB^−/−IRF7^−/− and FcγRIIB^−/− and mice is shown in the bar graphs. LZ, light zone; DZ, dark zone.