Fig. 7.

JAK/STAT signalling and FasIII in wing disc hinge folds. Third instar wing imaginal discs are shown with ventral to the right. The position of the proximal (P), medial (M) and distal (D) folds are indicated. Genotypes as indicated. (A) Wild-type disc showing 10xSTATGFP reporter activity, the ptc-Gal4 expression domain and DNA. The dotted box indicates the region shown in C,G,J-M. (B,B′) xz section through the midline of a third instar wing disc showing 10xSTATGFP reporter and FasIII expression. Arrowhead indicates lateralised FasIII. (C) xy image of a 10xSTATGFP containing wing disc expressing an RNAi targeting Stat92E mRNA. Loss of reporter activity indicates RNAi efficacy and expression domain. Dotted lines indicate the positions of the indicated xz sections shown in D-F. (D-F) xz sections of the disc shown in C showing fold morphology. Disruptions of the M and P folds are indicated by white arrowheads. (G) xy image of a 10xSTATGFP-containing wing disc expressing an RNAi targeting FasIII mRNA. Loss of FasIII indicates RNAi efficacy and expression domain. Dotted lines indicate the positions of the indicated xz sections shown below. (H-I′) xz sections of the wing disc shown in G showing fold morphology and FasIII. A shallowing of the M fold lacking FasIII is evident (white arrowheads). (J-M) xy images of wing imaginal discs stained for DNA to visualise fold morphology. Zfh2-Gal4 expression is shown in red (J). RNAi knockdown of Rh4 acts as a negative control whereas RNAi targeting FasIII or Stat92E disrupts the M fold (white arrows). Scale bar: in M, 100 μm.