Fig. 3. Complementary domains of Iro-C expression and Dpp activity in the second instar wild-type wing disc. Iro-C protein, green; Dpp pathway markers, red. (A,B) dpp expression (revealed by dpp-lacZ) preceeds that of Iro-C and it does not occur or it only occurs at very low levels within the Iro-C domain, the presumptive notum (arrowhead). (C,D) Dpp pathway activity (pMad protein) is reduced within the Iro-C domain (arrowhead). (E,F) Iro-C (yellow and green) is expressed within the domain of high accumulation of tkv-lacZ (red and yellow).