Fig. 4: SHM takes place in DZ B cells in the CDK2^low G0-like state.

a, Sorting gate (left) and examples of GC B cells with nuclear (CDK2^low) and cytoplasmic (CDK2^hi) DHB–tdTomato reporter as identified by image-based cell sorting (right). See Extended Data Fig. 7a,b for full sort strategy and further examples. b, Left, assignment of cell-cycle phase to CDK2^hi and CDK2^low DZ B cells by expression of S-phase and G2–M transcriptional signatures. Right, quantification. Cell-cycle categories are assigned using the CellCycleScoring function in Seurat. G0–G1 cells are defined as those lacking expression of S-phase and G2–M-phase transcripts. c, Left, number of Ighv + Iglv mutations in CDK2^low and CDK2^hi B cells 72 h after treatment with anti-DEC-OVA. Each symbol represents the mean of one mouse and is scaled according to the number of cells sequenced; line is the mean of all CDK2^low B cells. P value by paired t-test. Middle, difference between mean CDK2^hi and CDK2^low B cells in each mouse. Right, distribution of mutations in pooled CDK2^low and CDK2^hi B cells. Horizontal black line shows the mean. P value by Kolmogorov–Smirnov test.