Figure 3. Expression of upd and activation of JAK/STAT pathway signalling in the wing disc.

Proximal (P), medial (M) and distal (D) folds are labelled. Scale bar is 100 µm, (A & B) Third instar wing imaginal discs showing the expression of upd mRNA in wild type (A) and os^o (B) individuals. Expression of upd within the P fold (arrow) is lost in the os^o mutant. (C & D) Third instar wing imaginal discs showing DNA (white) and the 10xSTATGFP reporter (green) in wild type (C) and os^o (D) individuals. Reporter activity within the P fold (arrow) is greatly reduced in os^o mutants suggesting that JAK/STAT pathway ligands are not expressed in this area. (E) Schematic representation of the third instar wing imaginal disc fate map showing the regions labelled in Figure 2, the P, M and D lateral folds and the approximate regions of wild type upd expression (purple). Image based on fate map originally published in [25].