Erythroid progenitor (BFU-E, CFU-E) proliferation as inferred from 5'bromodeoxyuridine labeling.

Survival patterns of burst-forming unit-erythroid (BFU-E) and cluster-forming unit-erythroid (CFU-E) were studied in B6D2F1 mice after 5'bromodeoxycytidine (BrdCyd) infusion and near-ultraviolet (near-UV) light treatment. Comparison of the kinetics of BrdCyd sensitization of these colony formers with the kinetics of granulocyte-monocyte colony-forming cells (GM-CFC) and colony-forming unit-spleen (CFU-S) demonstrated a similar, but distinguishable, pattern of labeling between BFU-E and CFU-S. BFU-E and CFU-S each contain a subpopulation of unlabeled cells that diminishes with a half-life of 35 to 40 hours. Subsequent comparisons of this close association of BFU-E and CFU-S in Sl/Sld mice, again, showed similar patterns of BrdCyd labeling without evidence of an unlabeled or G0 subpopulation. These results are discussed with respect to the likelihood of a precursor relationship between these two cell types.