Fig. 7. Third instar larval eye-antennal discs. (A,C,E,G) Wild-type discs, and (B,D,F,H) rn16/rn20 discs. Expression of Dac in wild type (A) and roe mutant (B) shows that Dac expression is unaffected and that general eye disc patterning appears normal. Dac further appears unchanged in the antennal spot. Expression of Boss (C,D) and Elav (E,F) reveals that the highly ordered array of developing photoreceptors observed in wild type (C,E) is affected in roe (D,F). Boss expression is apparently absent from some developing photoreceptor clusters (arrows in D), and Elav expression reveals clusters with reduced number of photoreceptors (arrows in F). (G,H) Expression of Dl. In wild type (G) Dl expression is observed in clusters at the morphogenetic furrow (arrow) and in subsets of cells posterior to it. In roe (H) the punctate expression of Dl at the furrow is affected and only present as a diffuse band (arrow). Posterior to the furrow, Dl expression is disorganized (H). Expression of Sca in wild type (I) and roe (J) is similar to Dl.
