Hematologic status of C3H/HeJ^wan homozygotes. (A) A C3H/HeJwan/wan newborn with a wild-type (+/+) littermate. Note the extreme pallor of the wan homozygote. (B) RBC volume and hemoglobin concentration histograms of whole blood from normal (+/+) and wan/wan (-/-) newborn mice. Significant populations of small (left panels) and dehydrated (right panels) RBCs are present in mutant blood compared with controls. (C) RBC counts are decreased in wan/wan fetuses compared with normal littermates. The differences are significant (^*P < .001) by fetal day 18 and at birth. (D-E) Wright-stained peripheral blood smear from a newborn C3H^+/+ mouse (D) and a mutant C3H^wan/wan mouse (E). Many RBC fragments (arrowheads) and membrane projections (arrows) are evident in mutant blood smears. Bar = 10 μM. (F-H) Scanning electron photomicrographs of normal (F) and mutant (G-H) RBCs. Mutant RBCs are predominantly spherocytic (G) with frequent membrane projections (H). Bar = 1 μM.