Unrearranged d432β-Αγ 3′RE vector is present in the genomic DNA from PB leukocytes and spleen cells of animals 32 weeks following transplantation with vector-transduced BM cells.

Southern blot analysis, using a ³²-P labeled RRE probe, of the indicated genomic DNA digested with BglII. This enzyme cuts once in the 5′ LTR and immediately inside the 3′ LTR of the integrated d432β-^Aγ 3′RE vector (Figure 1A), thereby liberating a near unit length proviral form. DNA samples are as follows: (plasmid) d432β-^Aγ 3′RE vector plasmid DNA mixed with genomic NIH3T3 DNA; (NIH3T3) NIH3T3 cells transduced with the d432β-^Aγ 3′RE vector; (Neg) naive NIH 3T3 cells; (1 copy) MEL cells harboring a single copy of d432β-^Aγ MSCV GFP (BglII digestion liberates a subgenomic vector fragment); PB, and (Spl) spleen of the indicated mice. Genomic DNA (15 μg) was used in all cases except for the PB lanes, which contained 5 μg. The arrow indicates a 7.2-kb hybridizing fragment, which is of the correct predicted size of an integrated, unrearranged d432β-^Aγ 3′RE provirus.