Cells lacking Gfi1 and Gfi1b are still able to generate hematopoietic cells. (A) Number of hematopoietic colonies generated by yolk-sac cells with the indicated genotypes after 8 days of culture. Values in the histogram correspond to an average of 3 technical replicates; the error bars correspond to the SEM. (B) Cytospins from hematopoietic colonies from panel A were stained with O-dianisidine, May-Grünwald-Giemsa. Arrows indicate erythroid cells (brown staining); stars indicate macrophages.(C) FACS analysis of SCA1/KIT and CDH5/TIE2 expression among cells of the indicated genotypes after clonogenic assay. Numbers indicate percentages. (D) Quantitative RT-PCR analysis of hematopoietic colonies generated in clonogenic assay.