trc¹/trc⁸ mutant show a variable delay in developmental rate.

trc¹/trc⁸ mutant pupae can have multiply split laterals on the aristae. Laterals are seen to split at a wide range of developmental stages. As development proceeds, the distance from the proximal base of the lateral to the proximal most branch-point increases, as does the distance between the proximal and distal branch-points. An increase in the length of the arms distal to branch-points is also seen.

Hemizygous flies have branched arista laterals.

A majority of cells in the more central and proximal regions of adult trc⁸/Df(3L)kto2 wings produce multiple hairs. There is an average of 2.3 hairs per cell. Some hairs are split distally, but in most cells the multiple hairs appear to be separate but clumped closely together. When a wing cell produces a single hair, the hair appears to be normal in shape and length. The wings are often curved upwards mildly. Epidermal cells in other regions of these animals also form extra trichomes. The multiple wing hair phenotype appears milder early in morphogenesis in pupal trc⁸/Df(3L)kto2 wings than in adult wings. As hair extension proceeds the multihair phenotype becomes progressively stronger. Some hairs are split along the extending shaft while others appear to be separate down into the cell. Bristles with split shafts are seen in all regions of trc⁸/Df(3L)kto2 adult flies, although they are more frequent on the abdomen than in other body regions. There is substantial variation in the phenotype; in some flies 50% of the bristles of abdominal segment 3 or 4 are split, while in others less than 3% are split. Unbranched bristles are typically normal in shape. Most bristles show a single split, but examples of multiply split bristles are seen. The branches typically diverge at various points along the bristle shaft, while infrequently the split originates at the proximal end of the shaft. In general, when a bristle is split, both branches are thinner than the segment just proximal to the split. In addition, the thicker branch is routinely longer than the thinner branch. Actin bundles that extend continuously from an unbranched region into a branched region are seen and actin bundles appear normal. Many abdominal bristles also have abnormal polarity, frequently pointing towards the dorsal midline. trc¹/trc⁸ clones in the wing produce a weak multiple hair cell phenotype. Some hairs are split distally. The hairs appear clustered close together. In some cases the hairs are oriented almost orthogonally to the plane of the wing. trc¹/trc⁸ flies routinely show branching of one or more of the lateral extensions of the antenna. trc⁸ pupae are more sensitive to the effects of cytochalasin D on the bristles than wild-type pupae. The injection of stauroporine significantly increases the frequency of split bristles in homozygous flies.