Homozygous mutant clones in the developing eye induces apoptotic cells in the eye, but only about 10 ommatidial columns posterior to the morphogenetic furrow.
Dorsal medial cell numbers vary between 2 and 6 per embryo.
Heterozygous flies have essentially wild-type eyes. Homozygous clones in the eye are always associated with a scar, surrounded by normal ommatidia of mixed genotype.
Enhances the ro phenotype: eyes from rox63/rox63, S126/+ double mutant flies are severely reduced in size and disorganised, and individual ommatidia contain only 3-4 photoreceptors.