Hematological characterization of anemic mice homozygous for S1 allele at steel locus

Abstract

Adult S1/S1 mice when compared to normal +/+ littermates suffer from macrocytic anemia with normal absolute reticulocyte count and leukopenia. Femoral marrow cellularity is reduced two-fold with increased frequency of benzidine-positive (erythroblastic) and decreased frequency of peroxidase-positive (granulocytic) cells. The relationships are reversed in the spleen, where total cellularity is normal. CFU-S cells from S1/S1 mice from equivalent numbers of exogenous spleen colonies in lethally irradiated recipients to CFU-S from +/+ mice. Moreover, there is a similar cellular composition in these colonies. However, marrow cells from S1/S1 mice form twice reduced numbers of erythroblastic bursts in diffusion chambers and the formation of early erythrocytic colonies (CFU-E-derived) in diffusion chambers is reduced nearly ten times in the case of S1/S1 marrow cells. Endogenous spleen colony formation is nearly absent in S1/S1 mice following 100 cGy of X-irradiation both at 5 and 10 post-irradiation days. In +/+ mice, hemopoietic regeneration of the spleen following this dose is abundant. In conclusion, S1/S1 mice possess similar but slightly more severe defects of hemopoiesis than S1/S1d mice. As can be seen in the latter model this is dependent on altered hemopoietic environment in S1/S1 animals.