Expression of crbintra.Scer\UAS under the control of Scer\GAL4GMR.PF of Scer\GAL4sev.EP.M results in a rough eye phenotype, characterised by perturbations of the regular pattern of ommatidia and occasional bristle duplications. In pupal eyes that are expressing crbintra.Scer\UAS under the control of Scer\GAL4GMR.PF, the number of interommatidial (lattice) cells (IOCs) is increased compared to wild type, and sorting of these cells fails to occur in many instances. Many of the surplus IOCs are aligned side-to-side instead of end-to-end, so that two cell rows are found between many ommatidial cell clusters. The secondary and tertiary pigment cells are often arranged "astrally", with four cells (instead of the usual three) surrounding a bristle cell. This results in the ommatidia adopting a square rather than a hexagonal shape. Larval eye imaginal discs expressing crbintra.Scer\UAS under the control of Scer\GAL4GMR.PF show a strong reduction in the number of apoptotic cells posterior to the morphogenetic furrow. In pupal eye discs, however, suppression of apoptosis is less pronounced and is only visible in small patches in the disc.
The degree of wing disc overgrowth caused by expression of crbintra.Scer\UAS under the control of Scer\GAL4en-e16E increases as transgene expression levels are elevated.
Overexpression of crbintra.Scer\UAS, under the regulation of Scer\GAL4en-e16E results in severe tissue disorganisation in the wing, which is attributed to 'apicalisation' of the wing disc cells and causes strong cuticular defects.
Overexpression of crb results in an expansion of the apical membrane domain accompanied by a reduction of the basolateral membrane domain. The amnioserosa cells lack apical zonula adherens junctions (ZA), spot adherens junctions (SAJ) are also abnormal.