The origin of pattern duplications in segment polarity mutants of Drosophila melanogaster.

Mutations of the segment polarity group in Drosophila melanogaster produce additional denticles with reversed polarity in every segment of the larval cuticle. We have investigated the effect of mutations in different elements of the bithorax complex on the segmental identity of these additional pattern elements. Our results suggest that they are derived, primarily, from the anterior compartment of each segment.