The structure of peripheral lymphoid organs and serum immunoglobulin levels are not affected by the C481S substitution. (A-B) Immunofluorescence staining of spleen and lymph nodes sections. Labeled Abs against B220 (red), MOMA-1 (green), and TCRβ (cyan) were used for spleen and B220 (red) and TCRβ (cyan) for lymph nodes. Scale bar, 200 μm. (C) ELISA was performed for total IgG, IgM, and IgG3; serum from 5 wild-type and 5 C481S mice was diluted to indicated concentrations. (D) Anti-DNA total IgG, IgM, and IgG subtypes Abs were measured by ELISA. Each dot represents data from individual animals, error bars indicate standard deviation (SD) of the mean and unpaired 2-tailed Mann-Whitney U test was used to calculate significance.