Molecular and genetic characterization of , a new dominant allele of in D. melanogaster.

Dominant gain-of-function alleles for the homeotic gene ( ) have been known for a long time. They are summarized under the name ( ). Such alleles are rather easy to spot because the morphology of the conspicuous dorsal wing appendage is often dramatically changed. The majority of these alleles is associated with chromosomal rearrangements that alter the genetic landscape of the locus. Thereby, UBX protein is ectopically expressed in the wing primordium where it is normally absent. Since specifies haltere identity, wing cells expressing UBX are determined to become haltere cells. However, apart from the prototypic allele , information on the molecular details of alleles is scarce. Here, we present a rather detailed account on a novel Cbx-1-like allele called . The results of our study corroborate the model that has been postulated for the wing phenotype.