β lobes of the mushroom body cross the midline in approximately 50% of twf^EP3701 and 30% twf^EP3701/Df(3R)su(Hw)7 mutant animal brains. In severe cases, the two β lobes are completely fused. β loves are bifurcated and thickened. 10% of twf^EP3701 mutants display unilateral or bilateral loss of the adult mushroom body α lobe.

At 29[o]C, twf^EP3701 and twf^EP3701/twf¹¹⁰ mutant animals display a moderate but significant delay in border cell migration.

Homozygous flies are slightly smaller and less active than wild-type flies. They show reduced or completely lost flight ability. Hatching frequency of twf^EP3701 animals is slightly reduced, the larval period is significantly longer than normal, but the duration of the pupal period is wild type. No defects in border cell migration are seen in twf^EP3701 egg chambers. twf^EP3701 mutants have a rough eye phenotype. The interommatidial bristles are often tufted and the ommatidia are sometimes pitted and occasionally fused. All bristles show defects in morphology, with macrochaetae being more severely affected than microchaetae. The macrochaetae are shorter than normal and have a rough surface, with the ridges and grooves on the surface of the macrochaetae being highly irregular (in contrast to the completely straight ridges and grooves seen in wild-type bristles). The bristles often have a thicker portion somewhere along the shaft, and in this region the ridges are oriented perpendicular to the long axis. The tip of the bristle is not as thin as normal and has a smooth surface with only short, randomly oriented ridges. The macrochaetae, but not microchaetae, are often split, bent or branched. The hairs are also slightly shorter than normal. Mutant 48 hours old macrochaetae have a large number of small F-actin containing spots or tiny actin bundles. The spots are localised at the bristle surface between the main bundles and the tiny bundles appear to be oriented perpendicular to the long axis of the bristle.

tsr^k05633, twf^EP3701 has macrochaeta phenotype

tsr^k05633, twf^EP3701 has anterior dorsocentral bristle phenotype

tsr^k05633, twf^EP3701 has posterior scutellar bristle phenotype