Liver-specific loss of FPN responsiveness to hepcidin reduces fetal liver iron stores and hemoglobin. (A) Liver iron concentration in fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5 (n = 3, 3, respectively), day 0 (n = 3, 4), week 1 (n = 4, 3), week 4 (n = 4, 4), and week 12 (n = 3, 3) of age. P values are shown relative to fpnC326Y^fl/fl littermate controls at the respective timepoint. (B) Representative images of DAB-enhanced Perls’ iron stain in the livers of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5. (C) Extrahepatic iron concentration in fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates measured as carcass iron at e17.5 (n = 3, 5) and as splenic iron at day 0 (n = 3, 4), week 1 (n = 4, 3), week 4 (n = 4, 4), and week 12 (n = 3, 3) of age. P values are shown relative to fpnC326Y^fl/fl littermate controls at the respective timepoint. (D) Hemoglobin concentration in fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5 (n = 12, 6), day 0 (n = 4, 3), week 1 (n = 4, 3), week 4 (n = 4, 4), and week 12 (n = 3, 3) of age. P values are shown relative to fpnC326Y^fl/fl littermate controls at the respective timepoint. (E) Representative dot plots of erythroid progenitors from livers of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5. (F) Quantitation of erythroid progenitor populations R1 through R5 from livers of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5 (n = 5, 4). (G) Placental iron concentration in fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5 (n = 11, 6). (H) Relative expression of tfr1 and dmt1 mRNA transcripts in placentae of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre+ littermates at e17.5 (n = 3, 5). (I) Iron concentration in the serum of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5 (n = 11, 6). (J) Representative images of FPN immunostaining in the placentae of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre+ littermates at e17.5. (K) Western blot for FPN in the placentae of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre+ littermates at e17.5 (n = 3, 3). Normalized intensities are shown in supplemental Figure 5C. (L) Representative images of FPN immunostaining in the livers of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5. (M) Western blot for FPN in the livers of fpnC326Y^fl/fl animals and fpnC326Y^fl/fl, Alb.Cre⁺ littermates at e17.5 (n = 3, 3). Normalized intensities are shown in supplemental Figure 5D. Values are shown as mean ± SEM. P values are calculated using Student t test.