Immunohistochemical staining for Nramp2 in the intestine. Tissue sections were prepared as described in Materials and Methods and were immunostained with polyclonal rabbit antimouse Nramp2 (NT) antibody (A and D), preimmune serum (B and E), and polyclonal rabbit anti-mouse Bgp1 antibody (C and F). Sections were counterstained with methylene blue, before microscopic examination and photography. Low magnification (400×) of histological sections of proximal duodenum (I1; Fig 2) from mice fed with a control (A, B, and C) or low iron (D, F, and E) diet. Position of villi and crypts are identified. Arrows in (D) identify Nramp2 brush border staining (arrow), intracellular staining (arrowhead), or negative goblet cells (white arrow). In (C) and (F), arrows identify Bgp1 staining in the brush border and in the crypts (arrow), in the supranuclear intracellular region (arrowhead), and in the lumen (white arrow).