Homozygous embryos show no obvious defects. In a gl⁺/gl³ background heterozygotes show a dominant retinal mutant phenotype, the anterior half of the eye is rough, flattened and devoid of bristles. Ommatidia are sparse and isolated by massive pigment cells. Anterior clones in the eye have a phenotype similar to the heterozygote, clones in the posterior have no phenotype.