Abd-BFab-6.1 mutants show mixed anteriorizing (loss-of-function) and posteriorizing (gain-of-function) transformations of abdominal segments A5 and A6 towards A4 or A6. In the A6 segment, a gain of bristles is seen on the mutant sternite and a loss of pigmentation on the tergite, both indicative of an anterior-directed transformation (probably towards A4).