Retroviral expression of GATA-2 in hematogenic cells suppresses hematopoietic cell production. (A) Structure of the MSCV–GATA-2–IRES-EGFP and MSCV-IRES-EGFP retrovirus vectors. (B) Western blotting analysis showing modest GATA-2 expression in LO cells⁸  infected with the MSCV–GATA-2–IRES-EGFP virus (lane 2) and low level endogenous GATA-2 expression in the cells infected with MSCV-IRES-EGFP virus (lane 3). P815 mast cells were used as a positive control for this experiment (lanes 1). (C-D) Fluorescent microscopy analysis of V-GFP⁺ cells 9 days after culture. Cells infected by MSCV-IRES-EGFP (C) and MSCV–GATA-2–IRES-EGFP (D) are shown. The red arrow in panel C indicates the round-shaped V-GFP⁺ cells detached from the dishes. (E) Surface-marker profile of V-GFP⁺ cells infected with MSCV–GATA-2–IRES-EGFP virus or MSCV-IRES-EGFP virus. At day 7, 5.6% or 3.7% of cells were infected by MSCV–GATA-2–IRES-EGFP V-GFP⁺ virus or MSCV-IRES-EGFP virus, respectively. The bottom 3 panels demonstrate the CD34 and PCLP1 expression on the V-GFP⁺ cells at day 7. (F) The percentage of CD45+ cells. CD45+ cells in the fraction infected with either MSCV–GATA-2–IRES-EGFP virus (•) or MSCV-IRES-EGFP virus (○) in primary AGM culture. Original magnification, panels C-D, × 100.