Mutant embryos show the transformation of the thorax to the first abdominal segment and the abdominal segments to more posterior ones.

Homozygous embryos show partial transformation of head and thorax into abdominal structures, and partial transformation of abdominal segment A8 into A7. Heterozygous adult males show sex combs on the second and third legs with low penetrance.

Embryos have head defects, with a transformation of head, thorax and abdomen segments into more posterior structures. In Psc¹ Asx^unspecified double mutants, all denticle bands are similar to each other, and resemble A8 of wild-type embryos, although the thorax appears less transformed as the Keilin's organs are present. Head involution does not occur. A prominent abdominal denticle appears on the dorsal surface of the head and a few abdominal denticles are found behind the floor of the pharynx. Psc¹ Asx^unspecified Pcl^unspecified triple mutant embryos are characterised by a tandem array of posterior abdominal segments including up to four abdominal denticle bands in the head region. This phenotype is suppressed in embryos also lacking the bithorax complex region.

Asx^unspecified, Su(z)12¹ has mesothoracic leg phenotype

Asx^unspecified, Su(z)12¹ has metathoracic leg phenotype

Asx^unspecified, Su(z)12¹ has sex comb phenotype