Elongation of rhabdomeres is not affected in kst1/kst2 photoreceptors.
Rhabdomeres of kst1/kst2 mutant eyes show defects in rhabdomere shape similar to, but less marked than those of crb mutants. Stalk membranes are 10% shorter than wild type and lack the wild type deep folds.
Mutant embryos hatch, but mutant pupae are present at less than 10% of the expected number, suggesting that most individuals die as larvae. There seems to be little pupal lethality and kst mutants eclose 2-4 days behind their wild-type siblings. Adult escapers are very infertile and lay few eggs. Hemizygous and kst1/kst2 adult escapers have rough eyes. The R7 photoreceptor cell is missing in many ommatidia in kst1/Df(3L)HR232 escapers. Many ommatidia are missing in the eyes of kst1/Df(3L)1226 escapers. kst1/kst2 adult escapers have wings that typically curve downwards in an "inverted spoon" shape. Hemizygous adult escapers show a visible extrusion of melanised material from the abdominal spiracles.
Homozygotes generally die as larvae. Surviving adults have defects in the eyes, wings and tracheal system.
Hemizygotes have irregular or missing facets in a region of variable size at the posterior margin of the eye. The wings show a variable degree of downward curvature and the flies tend to "leak" haemolymph, particularly through the spiracles of the abdomen.