Description
All isoforms are required for patterning of the embryonic cuticle. Acts with exd to delimit the eye field and prevent inappropriate eye development. Isoforms that carry the homeodomain are required for proper localization of chordotonal organs within the peripheral nervous system and antennal identity; required to activate antennal-specific genes, such as sal and to repress the leg-like expression of dac. Necessary for the nuclear localization of the essential HOX cofactor, extradenticle (exd). Both necessary and sufficient for inner photoreceptors to adopt the polarization-sensitive 'dorsal rim area' (DRA) of the eye fate instead of the color-sensitive default state. This occurs by increasing rhabdomere size and uncoupling R7-R8 communication to allow both cells to express the same opsin rather than different ones as required for color vision.