Fig. 4. pixie mutant and Minute wing imaginal discs show regionally elevated levels of apoptosis. (A-L) Images are projections of confocal z-series taken through TUNEL-labelled wing imaginal discs that have been then inverted to reveal wing disc morphology, disc genotypes are indicated. Discs from (A,B) early to mid-third instar, (F,H) late third instar and (C-E,G,I-L) wandering larvae. Apoptosis is similar to control in discs heterozygous for pix^L17 (D) and pix^L35 (E), and is enhanced in discs that are transheterozygous for pix^L17 and M(3)66D¹ (J) and pix^L17 and M(3)95A¹ (L). Thin arrow in G indicates apoptotic nuclei that lie approximately at the DV boundary; thick arrow indicates those that lie at the pouch borders. (M) Bar charts and wing images showing that expressing p35 in the posterior compartment increases area in pix^L17/L35 wings (pix) compared with control (pix^L17/+). P/A ratio in pix wings is significantly higher than control, P=3.8x10^-10. White line in images on the right indicates the AP boundary. (N) Wg protein, detected by immunostaining, is ectopically expressed (arrow) when p35 is expressed in the posterior compartment of pixie mutant discs. Scale bar: 50 µm in A-L.