Fig. 5. Crb_intra expression prevents programmed cell death. (A-C) Wild-type, (D-H) GMR-Gal4>UAS-crb_intra. (A-F) Apoptotic cells visualised by Acridine Orange staining. (A-C) In the wild-type third-instar eye disc (A; eye, posterior to the left), dying cells appear anterior and posterior to the morphogenetic furrow (arrowheads). Cell death is also observed in the antennal region of the disc (ant). In pupae, fluorescent fragments of dying cells are visible throughout the disc at 31% p.d. (B) and in the perimeter clusters at 40% p.d. (C). (D-F) Cell death in GMR-Gal4>UAS-crb_intra larval discs (D) is strongly reduced posterior to the morphogenetic furrow (arrowhead), but still present anterior to the furrow and in the antennal disc (where GMR-Gal4 is not expressed). In pupal discs at 31% p.d. (E) cell death is locally suppressed (arrowheads), while at 40% p.d. cell death in perimeter clusters is not affected (F). (G,H) Elimination of perimeter clusters in pupal imaginal discs overexpressing Crb_intra, visualised by immunostaining for IrreC-rst (violet) and DE-cadherin (green). At 38% p.d. (G), the perimeter clusters can still be identified (arrowheads). At 42% p.d. (H), the perimeter clusters have been eliminated.