Figure 7. In vivo activity of Tg enhancers.

As diagrammed on the Left, the same enhancers used for co-transfection assays were tested for enhancer activity in transgenic animals in vivo. Whereas the full-length enhancer was strongly active in the cardiac cells (A), the truncated enhancer only showed very weak activity in a few Svp cells (B, and arrows in B). Mutation of the M-d MEF2 site in this truncated enhancer abolished reporter gene expression (C). Embryos are at stage 16 and oriented dorsal side uppermost and anterior to the left. Bar, 100μm.