Involved in eye morphogenesis. May be essential for the normal differentiation of ommatidial cells. Expression varies in tissues throughout development. At stage 5, expressed in the embryo dorsal region followed by expression in a striped pattern at stage 6. During gastrulation, expressed in ventral region and ventral nerve cord. Also detected in many neurons in the externa sensilla and chordotonal organ. At stage 16, expressed on the surface of the midgut. Additionally, expressed in a subset of cardioblasts (Tin+ subpopulation) during dorsal vessel formation. In third-instar larval tissues, expressed in the eye and antennal disks. In the antennal disks, expressed in the second antennal segments. In the eye disks, strongest expression found in the ocelli, and in the differentiating ommatidial cells. Also expressed in all cells within and in the vicinity of the morphogenetic furrow. Expressed in embryo from stage-5 onwards. Expressed in larvae. Truncated N-terminus. Sequence of unknown origin in the N-terminal part.