Fig. 7. GST-mediated dimerization substituted for the function of the Deltex RING-H2 finger motif. Transgenic flies carrying UAS constructs expressing Deltex derivatives fused to GST were crossed to ptc-GAL4 or ptc-GAL4/CyO;A101/TM6B. (A-L) Adult wings and high-magnification photographs. (M-R) The SOP cells in the third-instar wing discs are shown in green, and Deltex derivatives are shown in red. An enhancer trap line, A101, was used to visualize SOP cells. (A,G,M) Overexpression of Dx^full+GST did not produce a noticeable effect. (B,H,N) Overexpression of Dx^NBS+GST resulted in wild-type wings and discs. (C,I,O) Overexpression of Dx^PRM+GST gave wild-type wings and discs. (D,J,P) Overexpression of Dx^mRZF+GST resulted in the induction of a secondary wing margin-like structure and ectopic SOP formation (indicated by an arrow), which resembled the effect of Dx^full overexpression (see Fig. 3B,H,N). Note that Dx^mRZF (non-GST form) did not show a substantial effect under the same conditions (see Fig. 3E,K,Q). (E,K,Q) Overexpression of Dx^NBS-mRZF+GST resulted in wild-type wings and discs. (F,L,R) Overexpression of GST alone did not show a substantial effect.