AAV type 2-based erythromycin-inducible EYFP expression. (A) Schematic representation of pDF126 harboring a PhCMV-driven E-KRAB expression unit and pDF206/207/208 encoding EYFP transcribed by PETRON promoter derivatives containing 8 (pDF207), 4 (pDF208) and 2 (pDF209) E-KRAB-specific ETR operator modules. (B) Fluorescence micrographs of HT-1080 and MCF-7 co-transduced with pDF209/pDF126-derived AAV particles (1000 genomic particles/cell for pDF207/208/209 and 4000 genomic particles/cell for pDF126) and cultivated in the presence (+EM) and absence (-EM) of erythromycin (C) FACS-mediated quantification of EYFP expression in HT-1080. EYFP-specific FACS diagrams of HT-1080 co-transduced (4000 and 1000 genomic particles/cell) by pDF126/pDF207, pDF126/pDF208 and pDF126/pDF209 were cultivated for 48 h in the presence (+) and absence (-) of EM. Abbreviations: EM, erythromycin; EYFP, enhanced yellow fluorescent protein; ITR, inverted terminal repeat; KRAB, kruppel associated box; PETRON, erythromycin-inducible promoter.