Evaluation of three different promoters driving gene expression in developing chicken embryo by using in vivo electroporation.

To investigate the variance of exogenous gene expression driven by different promoters by in vivo electroporation, 3 plasmid vectors carrying different promoters were selected, and their driving strength was compared in developing chicken embryos. The 3 promoters included: 1) the CAG promoter (containing the cytomegalovirus (CMV) immediate early enhancer and the chicken β-actin promoter), 2) the CMV promoter (the human CMV immediate early region enhancer), and 3) the SV40 promoter (Simian virus 40). The intensity of GFP expression driven by the 3 promoters was detected by fluorescence microscopy. The results clearly showed that the expression intensity of the reporter gene differed significantly among the 3 promoters. Chicken β-actin promoter induced the highest intensity of GFP expression, while SV40 promoter induced the lowest intensity. Our results indicate that plasmids with appropriate promoters should be carefully selected to obtain strong exogenous gene expression by in vivo electroporation.