Circulating IgG and platelet-associated IgG in heterozygous pups delivered from immunized β₃^-/- mothers. (A) Circulating IgG against mouse β₃ integrin was detected in heterozygous pups (thin line) and pups of WT controls (filled area) by flow cytometry. (B) Platelet-associated IgG was detected in heterozygous pups (thin line) and pups of WT controls (filled area) by flow cytometry. Bar graphs represent means ± SEM fold increase of circulating IgG and PAIgG from heterozygous pups versus WT pups; n = 5-12.