Figure 4.

JNK signaling is involved in imaginal disc spreading and fusion, and it is necessary for the integrity of the larval tissue (A and B). The pattern of expression of the MZ980-Gal4 is revealed by the targeted expression of β-galactosidase. (A) Expression in the stalk region of third instar imaginal discs. (B) Expression in the dorsal junction and the scutellum of a 10-h APF pupa. (C) Mild thorax cleft observed after Puc overexpression with the MZ980-Gal4. (D) Weak thorax cleft observed in hypomorphic hep¹ animals. (E) Cellular defects associated to the strong hep^r75 condition. Larval cells disassociate from the imaginal epithelia and undergo premature apoptosis (arrowheads). No filopodia are observed, and the imaginal tissue detaches and initiates retraction.