Fig. 3. (A,B) Double staining of fng in situ hybridization (red) and mirr-lacZ expression (green) in second (A) and mid-third (B) instars. Arrowhead in B indicates the interface between fng and mirr expression. (B') Arrows show the potential Fng⁺-Fng^- interface in the ventral anterior regions of the eye disc as evidenced by fng expression. (C-E'') Regulation of fng expression by Slp and Iro as evidenced by fng in situ hybridization. (C) Clones ectopically expressing slp (green, arrows) show upregulation of fng transcription (red). (D) Clones ectopically expressing mirr (green, arrow) downregulate fng transcription (red). (E) When slp and mirr are co-expressed ventrally, fng transcription (red) is repressed in ventral (arrowhead), but not upregulated in dorsal (arrow) regions.