Fig. 5. GATA2 specifies hemangioblast development. (A) Blast colony formation in wild-type (WT) (J1) or Gata2^-/- ES cells. Values are mean±s.e.m. for three independent experiments; ^*, P<0.05 versus WT. (B) qRT-PCR of Scl (left panel) and Gata1 (right panel) in WT and Gata2^-/- ES cells. RNA was from D5 EBs and normalized against Gapdh. Values are mean±s.e.m., from qRT-PCR reactions perfomed in triplicate using two independent RNA samples; ^*, P<0.05 versus WT. (C) GATA2 induction scheme in differentiating EBs and formation of Blast colonies. Above is the scheme used to generate Blast colonies. Uppermost numbers indicate EB day. Lower gray bars indicate duration of Dox treatment and subsequent treatment of replated EBs. Below is a bar chart displaying Blast colony formation analyses of iGATA2 cells. The x-axis shows the day of EB harvest and replating to assay for Blast colony analysis. The key indicates whether or not Dox was added (1) at D2, during EB formation conditions (before slash); and (2) during growth in semi-solid replating media (after slash). Values are mean±s.e.m., average of three to five individual experiments; ^*, P<0.05; ^**, P<0.005. (D) EryP Potential of D2.75 iGATA2 EBs. Cells were grown in serum and treated with or without Dox at D2 and harvested and replated for EryP colonies on D2.75. Values are mean±s.e.m. from two to four independent experiments; ^*, P<0.05 versus untreated.