Fig. 5. AE1 specificity between ftz and Scr may be determined by promoter competition. AE1 can activate Scr/reporter expression in transgenic embryos containing divergently transcribed white-Scr promoter/reporter pairs (A-D, see Fig. 2 legend for general descriptions). AE1 activates white (A, white expression) but not the Scr/lacZ expression (B, lacZ expression). AE1-white interaction can be completely blocked by the intervening suHw insulator (C, white expression) with a moderate concomitant increase in the level of AE1-Scr interaction (D, lacZ expression). The insets show the internal control Scr expression (see Fig. 2 legend, and Materials and Methods for details).
