Wgn and Moe are required in R8 to regulate R2–R5 axonal targeting.

<p>Eye-brain complexes at third-instar larvae stage were labeled with <i>Ro-tau-LacZ</i> marker and stained by anti-beta galactosidase antibody. (A) <i>wgn</i>²²<i>/y</i> mutants showing R2–R5 mistargeting (arrows). (B) <i>wgn</i>²²/y mutants carrying one copy of <i>UAS-wgn</i> transgene under control of the R8 specific driver <i>109.68-Gal4</i> showed rescued R2–R5 axon mistargeting. (C) RNAi knockdown of Wgn only within R8 cells resulted in R2–R5 mistargeting into the medulla (axons >5) and/or thicker R2–R5 axonal bundles (arrow). (D) <i>moe^G0323/y</i> mutants with R2–R5 mistargeting (arrows). (E) <i>moe^G0323/y</i> mutants carrying one copy of <i>UAS-moe</i> transgene under control of the <i>109.68-Gal4</i> show substantial rescue. (F) RNAi knockdown of Moe within R8 resulted in R2–R5 axonal mistargeting (arrows). (G–I) Phenotypes were normal in larvae carrying <i>109.68-Gal4</i> driver (G), <i>UAS-wgn-RNAi</i> transgene (H) or <i>UAS-moe-RNAi</i> transgene (I). (J) Quantification of the number mistargeted of R2–R5 axon bundles presented in medulla in R8 specific knock down of Wgn or Moe or in R8 specific overexpression of Wgn or Moe in <i>wgn</i> or <i>moe</i> mutants, respectively. Double stars: P<0.001; Student T Tests, two tails. Error bars denote s.e.m. Genotypes in (J): #1(<i>wt¹¹¹⁸</i>/<i>y</i>; <i>Bc</i>/+; <i>UAS-wgn-RNAi/rtl</i>); #2(<i>wt¹¹¹⁸</i>/<i>y</i>; <i>109.68-Gal4</i>/+; <i>UAS-wgn-RNAi/rtl</i>); #3(<i>wgn²²</i>/<i>y</i>; <i>109.68-Gal4</i>/+; <i>+/rtl</i>); #4(<i>wgn²²</i>/<i>y</i>; <i>109.68-Gal4</i>/+; <i>UAS-wgn-Flag/rtl</i>; #5(<i>wt¹¹¹⁸</i>/<i>y</i>; <i>Bc</i>/<i>UAS-moe-RNAi</i>; <i>rtl/+</i>); #6(<i>wt¹¹¹⁸</i>/<i>y</i>; <i>109.68-Gal4</i>/<i>UAS-moe-RNAi; rtl/+</i>); #7(<i>moe^G0323</i>/<i>y</i>; <i>109.68-Gal4</i>/<i>+; rtl</i>/+); 8#(<i>moe^G0323</i>/<i>y</i>; <i>109.68-Gal4</i>/<i>UAS-moe-Myc; rtl</i>/+). Abbreviations: lp, lamina plexus; me, medulla; <i>rtl</i>, <i>Rough-tau-LacZ</i>. Scale bar: 10 µm.