Fig. 2. dGATAb is required for the specific transactivation of the Fbp1 EcRU by GAL4. Late third instar larval tissues from transgenic lines with the indicated genotypes (right-hand side) were dissected and histochemically stained for ß-galactosidase activity. Structures of the constructs in transgenic lines are depicted to the left-hand side, as in Fig. 1. Substituting UAS sites are indicated by hatched boxes. Disruptions of GBS2 and GBS3 are indicated by black crosses. Expression of the AE[UAS1] reporter construct in either the absence (A) or the presence (B) of the GAL4^daG32 driver is shown.