Breakpoint in Ubx.
Transformation of posterior portion of haltere toward wing, replacement of A1 tergite by post-notal tissue, no extra legs. A1 setal belt is intermediate between A1 and T3 type belts. Ventral pits on all abdominal segments.
Hemizygotes display ventral setal belt on the first abdominal segment is intermediate between the normal third thoracic belt and the normal first abdominal belts.
D. Baker.
The phenotype of a number of combinations of Ubx mutations has been investigated to determine the role of the bxd regulatory region in the modulation of Ubx expression.