The number of ommatidia is abnormal in heterozygotes.

The CQ neurons appear spatially disorganised in homozygotes. Approximately 70% of hemisegments contain a duplicated RP2 neuron. The two RP2 neurons are derived from two distinct ganglion mother cells (GMCs) that appear sequentially and do not share the same parental neuroblast. The mutation does not affect the formation and the first division of the longitudinal glia precursor. klu^unspecified Dr^unspecified double mutants show an additive phenotype with respect to gain of RP2 neurons.

Axon tracts are severely disrupted in homozygous embryos. The longitudinal connectives are often reduced in width or are completely missing in some segments. The commissures appear distorted and somewhat fuzzy. Development of ventral neuroblasts appears largely normal. An additional RP2-like cell is often seen adjacent to the normal RP2 neuron.