Ubiquitous loss of FPN responsiveness to hepcidin in the fetus reduces fetal liver iron stores and hemoglobin. (A) Liver iron concentration in fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 6, 5, respectively), day 0 (n = 5, 5), week 1 (n = 5, 4), week 4 (n = 3, 3), and week 12 (n = 3, 3) of age. P values are shown relative to fpn^wt/wt littermate controls at the respective timepoint. (B) Representative images of DAB-enhanced Perls’ iron stain in the livers of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5. (C) Extrahepatic iron concentration in fpn^wt/wt animals and fpn^wt/C326Y littermates measured as carcass iron at e17.5 (n = 6, 11) and as splenic iron at day 0 (n = 4, 6), week 1 (n = 4, 4), week 4 (n = 3, 3), and week 12 (n = 3, 3) of age. P values are shown relative to fpn^wt/wt littermate controls at the respective timepoint. (D) Hemoglobin concentration in fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 6, 7), day 0 (n = 3, 5), week 1 (n = 3, 5), week 4 (n = 3, 3), and week 12 (n = 3, 3) of age. P values are shown relative to fpn^wt/wt littermate controls at the respective timepoint. (E) Representative dot plots of erythroid progenitors from livers of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5. (F) Quantitation of erythroid progenitor populations R1 through R5 from livers of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 5, 3). (G) Placental iron concentration in fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 6, 11). (H) Relative expression of tfr1 and dmt1 mRNA transcripts in placentae of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 3, 5). (I) Iron concentration in the serum of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 5, 4). (J) Representative images of FPN immunostaining in the placentae of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5. (K) Western blot for FPN in the placentae of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 3, 3). Normalized intensities are shown in supplemental Figure 5A. (L) Representative images of FPN immunostaining in the livers of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5. (M) Western blot for FPN in the livers of fpn^wt/wt animals and fpn^wt/C326Y littermates at e17.5 (n = 3, 3). Normalized intensities are shown in supplemental Figure 5B. Values are shown as mean ± SEM. P values are calculated using Student t test. wk, week.