Quantification of spectrin-containing erythroid precursor cells in normal and perturbed erythropoiesis

The presence of spectrin in erythroid cells of female BALB/c mice has been detected by specific antisera to spectrin, using an immunofluorescent sandwich technique. Spectrin-containing cells are more numerous in bone marrow (18.9%) than in spleen (3.7%). In marrow, spectrin-containing cells exceed benzidine positive cells by about 6.2% whereas in spleen, numbers are almost equivalent. This suggests that normal proerythroblasts and perhaps more primitive erythroid cells contain spectrin, which is consistent with cytological characteristics of some spectrin-positive cells. Proerythroblast cells from spleens of Rauscher virus induced erythroleukemic mice contain spectrin although markers for hemoglobin synthesis are absent. Changes in CFUE number are closely correlated with those of spectrin-positive erythroid cells when erythropoiesis is perturbed. In red cell transfused, erythropoietically suppressed mice undergoing hemopoietic regeneration the administration of erythropoietin results in appearance of CFUE and spectrin-positive cells within 24-72 h. Due to different methods of assaying for CFUE and presence of spectrin, numerical data cannot be compared quantitatively because of uncertainty in the level of detection. Although it is not possible to demonstrate the presence or absence of spectrin in CFUE, changes in spectrin-containing cells and CFUE are closely correlated in time. Spectrin provides a convenient marker for both normal and leukemic nucleated erythroid cells and particular provides a functional marker for proerythroblasts which have previously been identified only by morphology.