UAS-inx7 expression disrupts joints and bristle patterns in developing legs.
Photograph of an adult leg from an animal of genotype DllGAL4 / +; UAS-inx73U(7X)8 /+. The DllGAL4 (distalless pattern) line drives expression of UAS-inx7 throughout the developing leg. The observed disruption of tarsal joints is a phenotype consistent with perturbation of Notch pathway signaling and is also seen when expressing UAS-ogre and UAS-inx2 using this driver line. An unusual feature, that is uniquely observed for UAS-inx7, is the appearance of many thick bristles in the tarsal segments (arrows). This phenotype is somewhat similar to that observed in legs mutant for Enhancer of split E(spl) complex genes ( de Celis et al, 1998). Members of the E(spl) family of transcription factors are downstream targets of the Notch signaling pathway. The qualitative differences of phenotypes seen between expression of UAS-inx7 in the developing wing and leg compared to the expression of UAS-ogre and UAS-inx2 suggest that inx7 may have a different ‘activity’ than the other innexins. inx-7 produces strong Delta-like phenotypes in the wing and extra-hairy leg segments, the other innexins are good at producing Serrate-like phenotypes in the wing and joint loss in the leg. T – tarsus.