Fig. 3. Su(z)12 function is required throughout development to repress HOX genes. Wing imaginal discs with clones of cells that are homozygous for the indicated Su(z)12 allele were stained with antibodies against GFP (green) and Ubx or Abd-B protein (red) as indicated. Neither Ubx nor Abd-B proteins are normally expressed in the wing imaginal disc. In each case, homozygous Su(z)12 mutant cells are marked by the absence of GFP protein (green) and in all experiments the Minute technique was used (see text). (A) Clones were induced 96 hours before analysis. Strong misexpression of Ubx and Abd-B protein is detected in clones that are homozygous for the strong alleles Su(z)121 and Su(z)124; note that both homeotic genes are derepressed in almost all clones, throughout the disc. In clones homozygous for the hypomorphic allele Su(z)122, misexpression of Ubx occurs only in clones in central regions of the wing pouch and in the hinge region; Abd-B is not derepressed in these clones. No derepression of Ubx or Abd-B is detected in Su(z)125 mutant clones, consistent with the genetic data that this allele is a weaker hypomorph than Su(z)122. (B) Kinetics of derepression of Ubx and Abd-B in Su(z)121 and Su(z)124 mutant clones. 48 hours after clone induction Ubx is still repressed in almost all Su(z)124 mutant clones but Su(z)121 mutant clones in the wing pouch already show strong misexpression of Ubx. 72 hours after clone induction, most Su(z)121 mutant clones show strong misexpression of Ubx, whereas only Su(z)124 mutant clones in the pouch show strong Ubx signal and Ubx is apparently still repressed in other regions of the disc.
