Figure 3. Dlp and Dally enhance the effects of Wif1 expression in Drosophila wings.

(A–L) nub-Gal4 is used to drive transgene expression. (A) Wild-type wing. (B) Overexpression of UAS-dlp results in only slightly fewer bristles along the wing margin, no loss of L1 and no reduction in wing size. For a detailed comparison of bristle numbers, see Figure S3. (C) Expression of UAS-wif1 eliminates many bristles, interrupts L1 (arrow) and somewhat reduces wing size. (D) Co-expression of UAS-dlp and UAS-wif1 almost completely eliminates wing margin bristles and L1, and strongly reduces wing size. (E) Expression of UAS-wif1 causes much weaker wing margin defects in dlp^A187/+ heterozygotes. (F) Overexpression of UAS-dally results in only very slightly fewer wing margin bristles and no obvious reductions in wing size. For detailed comparison of bristle numbers see Figure S3. (G) Combined expression of UAS-dally and UAS-wif1 almost completely eliminates wing margin bristles and L1, and further reduces wing size. (H) Expression of UAS-wif1 causes weaker wing margin defects in dally⁸⁰/+ heterozygotes (e.g. more complete anterior L1; compare arrows in C and H). (I–L) EGF-depleted Wif1 is less effective at inhibiting Wg signaling and does not interact with Dlp. Control wings expressing pVal-UAS-wif1 show modest defects in margin development (I), which is synergistically enhanced by UAS-dlp; the arrow marks the interruption of L1 and the asterisks mark scalloping of the margin (J). pVal-UAS-wif1ΔEGF is less effective at reducing number of margin bristles than pVal-UAS-wif1 and its effects on wing margin development are not enhanced by co-expression of UAS-dlp (J). See Figure S3 for comparison of bristle numbers.