Figure 2

Illustration of the total construct and the reading frame shift introduced to ensure expression of both resistance genes only in case of successful double transfection. The reading frame shift introduced into the both FRT vectors leads to expression of both resistance genes only after successful stable integration (green ticks), and not before (red x). The introduction of an additional C between the start codon (ATG) and the FRT site is indicated. This allows reliable selection of double-transfected cell clones (sequence elements for bacterial expression are not shown) and expression of genes of interest cloned into the multiple cloning sites (MCS) from identical promoters. (PSV40 SV40 promoter, SV40 pA polyA signal of SV40, PCMV CMV promoter; bGH pA polyA signal of bovine growth hormone).