Clonality analysis of secondary CFU-S from mice transplanted with HaMDR1-transduced BM cells.

Two mice from mixing experiment 1 were killed 24 and 20 weeks after transplantation, and bone marrow-derived CFU-S colonies were harvested 12 days after injection into irradiated mice. DNA was prepared from each CFU-S colony and analyzed for vector integration sites by Southern blot analysis. Because the probe is upstream of the 5′EcoRI site in the vector, each band represents a unique integration site within a CFU-S clone. The left panel shows the analysis of 7 clones derived from mouse 12, and the right panel shows 11 clones from mouse 10. DNA from a normal spleen (control) shows a faint endogenous band hybridizing with the MDR1 probe fragment. The DNA ladder is shown on each gel, and the ladder marker sizes are indicated on the left. Small arrows in the right panel indicate unique retroviral integration sites in a parent stem cell clone.