Gata2 knockdown in wild-type (WT) and Gata1⁻ cells derived from in vitro differentiation of embryonic stem (ES) cells. (A) Five-day-old embryoid bodies were disrupted and the cells were transduced with Banshee control (C) or Banshee shGATA2 retrovirus. Twenty-four hours later, GFP⁺ cells were purified by flow cytometry and analyzed for Gata2 expression by RT-PCR. Gata2 mRNA expression normalized to Gapdh mRNA is assigned a value of 1.0 in control virus–infected cells from WT and Gata1⁻ embryoid bodies. Error bars represent SD. (B) Representative flow cytometric analysis of Banshee control– and Banshee shGATA2–infected wild-type (WT) and Gata1⁻ hematopoietic progenitors derived from embryoid bodies. The numbers indicate the percentage of high Mac-1⁺ F4/80⁺ cells within the GFP⁺ population.