Fig. 7. bab expression is repressed by Dac, Sal and Hth in the antenna. (A) Wild-type expression of Bab (purple in all panels) and Dac (green in A,B,D). (B) Bab is derepressed in dac null clones in a3 (arrowheads). (C) bab expression expands proximally (arrowheads) into a3 in dac-lacZ/dac4 discs. Green is ß-galactosidase produced by the dac-lacZ element and marks where Dac would have been expressed. Note the extensive overlap (white) in C not seen in A. (D) bab is repressed by ectopic Dac produced in flipout clones (arrowheads). (E) Wild-type expression patterns of Bab and Sal (green). Sal-expressing cells were visualized by use of an anti-ß-galactosidase antibody in a sal-lacZ background. (F) bab is derepressed in sal null clones in a2 (arrowheads). Clones are marked by the absence of Myc (green). (G) bab is repressed by ectopic Sal (green) produced in a flipout clone (arrowheads). (H) Wild-type expression of Bab and Hth (green in H-J). (I) bab is activated in hth null clones (arrowheads). (J) bab is repressed by ectopic Hth (arrowheads) produced in the dpp pattern. The dpp pattern is dynamic (Masucci et al., 1990; Weigmann and Cohen, 1999), and Bab is not detected in cells exposed to high levels of Hth earlier in development (arrows in J).
