(A) Schematic comparing C3^+/–, C3^–/–, and C3 NIMA mice, or C3 NIMA mice after MMc depletion or displacement. d20, day 20. (B) Serum C3 levels in the male (square) or female (circle) mice described in A. (C) E. coli CFU after infection for male C3^+/–, C3^–/–, C3 NIMA, and C3 NIMA mice depleted of OVA⁺ MMcs using anti-OVA IgG. (D) Genome equivalent (GEq) OVA DNA specific to OVA⁺ MMcs in male C3 OVA NIMA mice 14 days after anti-OVA compared with isotype control IgG administration. (E) E. coli CFU after infection for female C3^+/–, C3^–/–, virgin C3 NIMA, and C3 NIMA mice postpartum after pregnancy sired by C3^–/– males. (F) GEq OVA DNA specific to OVA⁺ MMcs among female C3 OVA NIMA mice 20 days postpartum after pregnancy sired by C3^–/– males compared with age-matched virgin control mice. Each point represents data from an individual mouse, combined from at least 2 independent experiments, each with similar results. Data indicate the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.005, ****P < 0.001, as determined by 1-way Brown-Forsythe and Welch ANOVA test for comparing data containing more than 2 groups with nonuniform SD (B), 1-way ordinary ANOVA for comparing data containing more than 2 groups with similar SD (C and E), and unpaired Student’s t test when comparing 2 groups (D and F).