Impaired postnatal survival of T-E(M) mice. Th3/+ (Th3) mice were bred with ERFE-overexpressing Line-M (E[M]) mice. (A) Expected and observed percentages of generated offspring with specified genotypes at either 3 weeks after birth or in utero at embryonic day E18.5. Total numbers are in parentheses next to percentages. (B-H) Pups were harvested at E18.5, and blood and fetal livers were collected for analysis. Blood: (B) RBC counts, (C) Hb level, (D) hematocrit, (E) MCV. Fetal liver: (F) Erfe mRNA, (G) Hamp mRNA, and (H) nonheme iron concentrations. Statistics: (A) significant differences from expected proportions were assessed using χ² test (∗∗∗∗P < .0001). (B-H) P values were assessed using two-tailed unpaired t test (∗∗∗∗P < .0001) between the Th3 and T- E(M) groups only.