FIG. 1.

Summary of Flp-In/TetR system. (A) Schematic representation of plasmid constructs and positions of primers used for establishment of TREx BCBL1-Rta cells. P1 to P7 are primers, as detailed in Table 1. pFRT/lacZeo contains the FRT site for site-specific recombination downstream of the initiation codon (ATG) and expresses lacZ-Zeocin fusion protein (lacZ-Zeo) driven by the SV40 early promoter. pcDNA6/TR constitutively expresses TetR driven by the CMV promoter and also expresses the blasticidin resistance gene (Blast) driven by the SV40 promoter. pOG44 contains Flp recombinase (FLP), which mediates the FRT site-specific recombination. pcDNA5/FRT/TO-Rta contains the FRT site followed by the hygromycin resistance gene (Hygro), which carries neither its promoter nor its start codon. This vector also contains myc/His-tagged Rta cDNA (Rta) downstream of the CMV promoter and tetracycline operator sequences (CMVp/2xTetO₂). (B) Schematic diagram of the establishment of TREx BCBL1-Rta cells. Plasmid vectors and drugs used to establish the system are depicted with blue and red letters, respectively. R, resistant; S, sensitive.