Cyclin D2 is dispensable for inertial B cell cycling (related to Fig. 3 ). (A–C) Expression of Ccnd2 in UMAP dimension (A), over time after DEC-OVA immunization (B), and in LZ or DZ (C). P values in B are from a Kruskal–Wallis test with Dunn’s multiple comparisons test. Other significant P values are <0.001 (12 × 60 h), 0.0013 (12 vs. 30 h), and 0.037 (Ly75−/− vs. 12 h). (D) CRISPR/Cas9-mediated gene targeting strategy to introduce a 4-bp deletion and premature stop codon in Ccnd2. (E and F) Staining for B1 (left) and B1-a (right) cells isolated from peritoneal cavities of WT (Ccnd2+/+) or cyclin D2–deficient (Ccnd2−/−; E) mice, quantified in F. (G) Experimental setup for induction of GCs containing WT (Ccnd2+/+) or cyclin D2 mutant (Ccnd2−/−) B1-8hi cells. (H–L) DZ and LZ staining (H) and S phase entry (J) in WT (Ccnd2+/+) or cyclin D2–deficient (Ccnd2−/−) B1-8hi GC cells 12 d after NP-OVA immunization, quantified in I, K, and L. (M) Experimental setup for induction of GCs containing mixtures of WT (Ccnd2+/+) or cyclin D2 mutant (Ccnd2−/−) B1-8hi cells. (N) Clonal expansion of WT (Ccnd2+/+) or cyclin D2 mutant (Ccnd2−/−) B1-8hi cells over time, relative to day 7 (represented by a dotted line). *, P < 0.05; **, P < 0.01; n.s., nonsignificant, nonparametric Mann–Whitney test, compared with WT (Ccnd2+/+; G, I, and J) or day 7 (L). Bars indicate median. Each circle represents a mouse. Data are pooled from two independent experiments. Padj, adjusted P value.