Axonal polarity in Drosophila wings with mutant cuticular polarity patterns.

In Drosophila melanogaster certain mutations alter the polarity of trichomes and bristles, cuticular structures secreted by the epithelial cells of the adult fly. Since sensory neurons arise from epithelial cell precursors, and sensory axons grow along the inner faces of epithelial cells, we have studied the developing wings of these mutants to see whether the change in epithelial cell polarity has an influence on the direction of axon outgrowth. The nerve patterns formed in the mutants prickled, inturned, and frizzled, however, were largely normal, indicating that in these cases the polarity of the cuticular structures produced by the epithelial cells is altered without any effect on the polarity of the associated axons.