Fig. 6

α-retrovectors are not mobilized by the BXV1 xenotropic γ − retrovirus in EndoC-βΗ2 cells. a EndoC-βΗ2 cells transduced with the non SIN γ-retrovector pPRIHy TVA encoding a selectable marker (HygroR) and the TVA receptor (EndoC-βΗ2-TVA) were further transduced with an α-retrovector, (RCANBP(A) CMV GFP-IRES-ZeoR) encoding a distinct selectable marker (ZeoR). Naive 293 T cells were exposed to the conditioned medium (CM) of the doubly transduced EndoC-βΗ2 cells and next divided and cultured into two petri dishes in presence of either hygromycin or zeocin. After 10 days, exposed and selected 293 T cells were fixed and colored with crystal violet. The same doubly transduced EndoC-βΗ2 derivative (EndoC-βΗ2-TVA RCANBP(A) CMV GFP-IRES-ZeoR) is used in Fig. 7b, showing that it is heavily positive for GFP expression. This experiment was done in duplicate, with similar results, and further confirmed using the CM of EndoC-βΗ2- transduced with both pPRIHy TVA and RCASBP(A) GFP-IRES-ZeoR) (not shown). b Same experiments as in (a), but naive 293 T cells were exposed to the conditioned medium (CM) of EndoC-βΗ2 harboring only one retrovector, as indicated, each encoding ZeoR. This experiment was done in duplicate, which gave similar results