Heterozygotes have severely reduced eyes, containing less than 30 ommatidia. The shape of the mutant eye resembles an inverted drop. No patterning defects are seen in the retina. Five-cell preclusters are not seen in the heterozygous eye disc at the time when multiple rows of developing ommatidia are seen in wild-type discs, and instead a single row of mature ommatidial clusters is seen. Massive cell death associated with absence of furrow progression is seen.

Mutants display locomotor activity rhythms with circadian periods, though with reduced penetrance (small sample size). Average period length of the locomotor activity is rather short.

Severe disruption of eye development. Heterozygotes with Dr¹ are semi-lethal, 10-30% adults survive to eclosion, surviving adults exhibit reduced eye, deranged bristle pattern on the thorax, abdomen, legs and wing margins and locomotor defects so the flies could hardly move. A similar phenotype is seen when heterozygous with Dr¹ revertant alleles and stg alleles. Heterozygotes with Wedge¹ only exhibit the reduced eye phenotype. Interact in trans with lesions in stg causing loss and derangement of bristles and loss of neuromuscular coordination.

The progression of the morphogenetic furrow in the developing eye disc arrests. The eye disc appears normal at the time of arrest. dpp expression is abolished (as assayed with a dpp-lacZ fusion gene).

Adult eyes are very reduced and rough with about 30 facets. Some rhabdomeres within ommatidia are fused. Eye disc size is reduced.

homozygous lethal