Absence of Cebpa in murine HSCs up-regulates Cd7 and Lck. (A) Lin⁻c-Kit⁺Sca1⁺ hematopoietic stem cells (HSCs) were isolated and purified from poly I:C–treated Cebpa^wt/wtMx1-Cre mice (wt cre⁺) and Cebpa^F/FMx1-Cre knockout mice (F/F cre⁺). mRNA expression levels of Cd7 and Lck were determined by RQ-PCR. Data are presented relative to expression of wt cre⁺ animals as mean plus standard deviation of at least 3 individual mice in both groups. (B) Purified HSCs from poly I:C–treated Cebpa^F/FMx1-Cre mice were transduced with either empty vector (vector) or Cebpa expression construct (Cebpa). Cd7 and Lck mRNA expression levels were determined in GFP⁺ infected cells 1 day after transduction. Data are presented relative to expression of empty vector–transduced cells as mean plus standard deviation of 4 reactions.