Expression analyses of GFP and GATA-1 in hematopoietic progenitors. (A) The Lin^- fraction from the bone marrow of the G1-HRD-GFP transgenic mouse was stained with APC-conjugated anti-c-Kit antibody and analyzed by FACS. The percentage of cells in each quadrangle is shown. (B) Immunostaining of intracellular GATA-1 in the sorted cells. Almost all GFP⁺ cells in the Lin^- fraction were GATA-1 positive (top panel). Most GFP^- cells in the Lin^- fraction were GATA-1-negative (middle). The Lin^-/c-Kit⁺/GFP^- fraction contains approximately half of GATA-1-positive cells (bottom panel).