SUPPRESSOR OF HAIRLESS, THE DROSOPHILA HOMOLOG OF THE MOUSE RECOMBINATION SIGNAL BINDING-PROTEIN GENE, CONTROLS SENSORY ORGAN CELL FATES

Suppressor of Hairless (Su(H)) is required at two stages of adult sensory organ development in Drosophila. Complete loss of Su(H) function results in a "neurogenic" phenotype in imaginal discs, in which too many cells adopt the sensory organ precursor cell fate. Su(H) is also involved in controlling the fates of sensillum accessory cells and is specifically expressed in two of these cells. Su(H) is the Drosophila homolog of the mouse J(kappa) RBP gene, whose product binds specifically to the recombination signal sequence of immunoglobulin J(kappa) segments. The Su(H) and J(kappa) RBP proteins are 82% identical over most of their length, and share with bacteriophage integrases and yeast recombinases a motif that includes residues directly involved in catalyzing recombination.