Fig. 7

In vivo excision of the internal control and enhancer detection cassettes of the Zebrafish Enhancer Detection (ZED) vector using Flipase and Cre recombinases. A: ZED F1 stable transgenic embryos showing strong red fluorescent protein (RFP) expression in the muscles were injected with Flipase mRNA. This injection caused reduction of RFP expression in some cells of the right side of the embryo (arrow) but not in the left side. RFP reduction upon Flipase mRNA injection was observed in 83% of the injected embryos (n > 200). B: Embryos from a F1 Z48-ZED stable transgenic line. C: Injection of Cre mRNA in these stable transgenic embryos from this line caused mosaic loss of GFP expression. The transition from the homogeneous expression promoted by stable insertion to a mosaic pattern due to Cre-mediated recombination was observed in 85% of the injected embryos harboring the transgene (n > 200).