Click on image to view larger version.

Fig. 8. Model for the role of Egfr/Ras signaling in the context of ommatidial
rotation. Raf/MAPK nuclear signaling to Pnt upregulates the transcription of
activating (spi) and inhibiting (aos) Egfr ligands and might
regulate transcription of additional genes important for ommatidial rotation.
Egfr/Ras signal via Canoe to affect cytoskeletal and/or cell junctional
elements (junctions are schematized as black oval regions on membrane). In
addition, Egfr signaling affects Flamingo localization (the effector
regulating this aspect is not known).