THE DROSOPHILA TISSUE POLARITY GENE INTURNED ACTS CELL AUTONOMOUSLY AND ENCODES A NOVEL PROTEIN

Mutations in the inturned (ill) gene result in abnormal wing hair pola rity and in many wing cells forming two or more hairs instead of the n ormal single hair, We have generated genetic mosaics in a number of di fferent experiments and find that the in gene is required in all regio ns of the wing and that it functions in a cell autonomous fashion. We report the molecular cloning of the irt gene, the molecular mapping of in mutations and the isolation and sequencing of an in cDNA clone. Th e in gene encodes a novel protein whose sequence suggests it will be m embrane bound, The oa ability of an in cDNA, the expression of which i s driven by the basal activity of the hsp70 promoter to rescue an iii mutation suggests that patterned expression of in is unlikely to play a role in the function of this gene.