Proliferation of erythroid progenitors in the Lin⁻, Sca-1⁻, Kit⁺ mouse bone marrow progenitor population is synergistically enhanced by DMOG and Dex. (A) Lin⁻, Kit⁺, Sca-1⁻ mouse bone marrow cells were cultured in SFELE medium with no additions (control), 333μM DMOG, 1nM or 100nM Dex, 333μM DMOG plus 1nM Dex, or 333μM DMOG plus 100nM Dex. Total cell number was counted daily and normalized to the number of cells added to the culture. Error bars show 1 SD. (B) May-Grünewald-Giemsa staining of bone marrow Lin⁻, Kit⁺, Sca-1⁻ cells after 11 days of culture in medium with 333μM DMOG plus 100nM Dex. The erythroid morphology of these cells is further confirmed by FACS and benzidine-Giemsa staining (supplemental Figure 6A,C). (C) Fetal liver BFU-E cells after 10 days of culture in the same medium as panel B. The erythroid morphology is further confirmed by FACS and benzidine-Giemsa (supplemental Figure 6B,D). By these assays 80%-95% of cells are erythroid.