Figure 3.

Loss of ubr3 activity induces apoptosis in eye imaginal discs. (a-b') ubr3 was knocked-down by Mirr-Gal4>RNAi in the dorsal compartment of eye disc. Dorsal is up as marked by GFP. Apoptosis was detected by activated caspase-3 (cleaved caspase-3 (Caspa3*)) staining (a-a') and TUNEL assay (b-b'). (c-d') In ubr3 mutant clones (GFP negative), Caspa3* is increased in eye disc (c) and wing disc (d). (e-e') Eye discs labeled with mitosis marker PH3. Knockdown of ubr3 does not affect PH3 levels. (f) Quantification of PH3-positive cells. There is no statistical difference between the dorsal compartment (ubr3 RNAi) and ventral compartment (control) of the eye discs, as analyzed by paired t-test (P=0.506 (two-tailed), n=9). Genotypes: (a, b and e) w;+/UAS-ubr3 RNAi 1; +/Mirr-Gal4