(A) Spleen cells from non-immunized YY1f/, γ1CRE and YY1f/f
γ1CRE mice were stained with various antibodies to identify total B cells (CD19+AA4.1+, upper panel) and germinal center B cells (GC-B, DUMP-IgD-GL7hiCD95hi, lower panel). Percentages and number of (B) total B cells, and (C) GC-B cells per spleen of YY1f/, γ1CRE and YY1f/f
γ1CRE mice. Fig A-C are from three independent experiments (n = 3 mice for each genotype). (D) We used ELISA to detect various isotypes of serum immunoglobulins from YY1f/, γ1CRE and YY1f/f
γ1CRE mice. The concentration of IgM, IgA, total IgG, as well as IgG subclasses, IgG1, IgG2 and IgG3 were measured from sera samples that were obtained from four experiments (n ≥ 4 mice for each genotype). Asterisks indicate p<0.001.