Structure and expression of the HOXB4 retrovirus.

(A) Schematic representation of the MSCV-HOXB4-IRES-GFP (B4-GFP) construct and the MIG (GFP) control vector. (B) Southern blot analysis of CB cells after 4 weeks in vitro culture hybridized with a GFP probe. (C) Immunoblotting of 293 cells transfected with the FLAG-tagged B4-GFP virus.