Transposition deletion breakpoint maps to an intron between the first and second exons in the protein coding region of the caup transcription unit.
Heterozygotes have a very mild phenotype with some thoracic bristles occasionally being missing. Double heterozygotes with Df(4)M101-62f or Df(1)260-1 have a much stronger phenotype, with some bristles missing at a high frequency. Homozygotes lack all bristles on the lateral part of the notum, so that only a median stripe of bristles remains. The mesothorax is narrower than normal, and has no notopleural suture. The scutellum is smaller than normal, and the wings are raised. caup1/Df(3L)iro-2 flies are viable and have a phenotype similar to caup1 homozygotes. caup1/caup1 flies carrying schs.PR develop tufts of bristles in the lateral part of the notum (that is normally naked in caup1 homozygotes) after heat shock.
Only the median strip of hairs remains on the notum.
Df(3L)iro-2, acHw-49c, ara1, caup1 has visible phenotype
Df(3L)iro-2, ara1, caup1 has visible | recessive phenotype
Df(3L)iro-2, acHw-49c, ara1, caup1 has mesothoracic bristle | lateral phenotype
Df(3L)iro-2, ara1, caup1 has postpronotum phenotype
Df(3L)iro-2, ara1, caup1 has mesothoracic bristle | lateral phenotype
Df(3L)iro-2, ara1, caup1 has scutum & microchaeta | lateral phenotype
ara1 caup1/Df(3L)iro-2 flies lack lateral macrochaetae and the most lateral of microchaetae of the notum. The humeral bristles are normal and have wild-type axonal projections in these flies although the humerus is not morphologically normal. Bristles of variable size are formed in the otherwise naked lateral region of the notum if the flies are also carrying acHw-49c, at a position corresponding to that of the posterior supraalar bristle. This bristle has a contralateral axon branch in about 70% of cases.
Isolated as a mutation that alters the pattern of bristles when doubly heterozygous with Df(4)M101-62f.