More severe pathology in HRI-deficient Fech^m1Pas/m1Pas mice. (A) Increased protoporphyrin level in the reticulocytes and rbcs of Fech^m1Pas/m1Pas mice deficient in HRI. The fluorescent porphyrin levels in blood cells were analyzed by FACS analysis (left panels). The numbers inside the peak represent the arbitrary mean values of PPIX in each genotype. FACS analyses of the fluorescent porphyrin in reticulocytes were performed after staining with thiazole orange (right panels). The values on the right upper quadrant are percentages of reticulocytes. Left panels: x axes are arbitrary units of fluorescent intensity. Right panels: x and y axes are arbitrary units of fluorescent intensity. (B) Liver pathology. The liver sections were stained with H&E. (C) Skin photosensitivity. The HRI^–/–Fech^m1Pas/m1Pas mice were extremely jaundiced, as can be seen by the yellow color in their ears, and were dead 6 hours after exposure to mercury vapor lamp. Photos were taken 4 days after exposure to the mercury vapor lamp for the HRI^+/– Fech^m1Pas/m1Pas mice and HRI^+/+Fech^m1Pas/m1Pas mice. Twelve- to sixteen-week-old mice were used for these experiments.