Df(3L)Aprt-21 dominantly enhances the position effect variegation of the w gene caused by In(1)wm4.
78% of Ubx130, Df(3L)Aprt-21, Trl13C triple heterozygotes have halteres that quite heterogeneous in size and larger than Ubx130 alone, also exhibiting a stronger phenotype than any two of the alleles used. The haltere becomes a wing -like structure with wing veins and hairs on the wing margin. Heterozygotes have an average of about 9 sex combs, compared to about 11 in wild-type. 30% of animals have bristles on segment abdominal segment 6 (wild-type have none).