Fig. 4.

The yki 3′ UTR is necessary and sufficient for Rox8-mediated mRNA decay in vivo. (A–F) Fluorescence micrographs of wing discs are shown. Rox8 overexpression dramatically suppressed the overgrowth induced by Myc-Yki-UTR (A and B) or Myc-Yki-UTR^M2 (E and F), but not that by Myc-Yki-UTR^M1 (C and D). Consistently, Myc-Yki expression from Myc-Yki-UTR or Myc-Yki-UTR^M2, but not from Myc-Yki-UTR^M1, was impeded by Rox8 (A–F). (G–N) Light micrographs of Drosophila adult eyes are shown. Compared with the GMR > GFP control (G), GMR > Rox8 displayed no obvious phenotype (H). However, overexpression of Rox8 significantly impeded tumor-like overgrowth triggered by ectopic expression of Myc-Yki-UTR (I and J) or Myc-Yki-UTR^M2 (M and N), but not of Myc-Yki-UTR^M1 (K and L). (O–Q) Fluorescent images of third instar larval wing discs. Expressing Rox8 strikingly attenuated the expression of GFP from GFP-UTR (O) or GFP-UTR^M2 (Q), but not that from GFP-UTR^M1 (P). (R) RT-qPCR and immunoblot assays were performed in cultured S2 cells. Rox8 overexpression decreased the expression of GFP-UTR and GFP-UTR^M2 at both the mRNA and protein level, but had no significant effect on that of GFP-UTR^M1. ***P < 0.001. ns, no significant difference. Magnification for I–N: 6.3×.