Figure 2

The activity of Ens-1 promoter in vivo involves similar domains as in cES cells. Epiblast cells of pre-primitive streak chicken embryos were cotransfected by electroporation with CMV-DsRed (used to visualize the transfected cells) and U3-GFP vector, in which U3 contains the whole promoter of Ens-1 (A-C). GFP expression was compared with U3 constructs presenting the MutS1 (D-F), the MutS2 (G-I), or the MutS3 (J-L) mutations (see Figure 1 legend). As negative controls, mutations on non-functional sites were performed upstream of site S1 (Mut Ctr1: deletion of site b, Figure 1A) (M-O) or at position -129 (Mut Ctr2: deletion of the GTGTG motif) (P-R). The same results were obtained in three independent experiments.