We analyzed if the Wg pattern was altered in these circumstances as it has been noticed in the presence of ``undead cells''
(D) BrdU staining (white) of the discs demonstrated in (A). (B, E) In RBF expressing discs, as in the control disc shown in (A,D), BrdU staining is homogeneous in the whole disc, apart from in the ZNC (Zone of Non-proliferating Cells) (white arrow). (C) In RBFD253A expressing discs, cells encompassing the sturdy RBF staining show an enhanced BrdU staining, indicating that these cells have an enhanced proliferation rate. (G) From still left to appropriate, genotypes of the larvae are: ptcGal4/+, ptc-Gal4/UAS-RBF, and UAS-RBFD253A X ptc-Gal4/+. (G) S phase staining by BrdU (eco-friendly), and RBF staining (red). (J) BrdU staining (white) of the discs revealed in (G) with enlarged view of boxed location. (G, J) BrdU staining is homogeneous in the complete disc, except in the ZNC (white arrow). (IL) In ptc.RBFD253A discs, cells inside the ZNC that are adjacent to RBFD253A expressing cells are labeled with BrdU, indicating an irregular proliferation of these cells. All discs are shown with posterior to the best. RBFD253A-induced apoptosis depends on the action of the JNK pathway. In summary, we demonstrated that RBF and RBFD253A activate the JNK pathway, that this pathway mediates equally RBF and RBFD253A -induced apoptosis, and is responsible for RBFD253A-induced overgrowth. As previously indicated, the JNK pathway is important to both RBFD253A-induced overgrowth, and more than-proliferation induced by ``undead cells. Its over-activation in ``undead cells prospects to ectopic synthesis and secretion of the mitogenic proteins Wg and Dpp in a lengthy lasting way, foremost to an more than-proliferation of neighboring cells and overgrowth phenotypes [43]. Because RBFD253A-induced overgrowth is dependent on JNK pathway activation, we wondered if this approach was provoked by a equivalent system. We thus Oltipraz co-expressed RBF and p35 in wing discs to produce undead cells dependent on RBF-induced apoptosis, and assess the wg expression sample in these discs to wg expression in RBFD253A expressing discs. In vg.RBF, p35 flies raised at 25uC, only one wing observed displayed overgrowth out of 123 flies counted. Therefore, even in the existence of p35, RBF does not seem to induce an overgrowth phenotype that would result from the existence of undead cells. However, at 29uC, more wings co-expressing RBF and p35 offered overgrowth phenotype (10 wings out of 35), but in such extreme situations only few flies hatched.