The sensory projections of Drosophila mutants which show abnormal wing formation or flying behavior

The central projection pattern of sensory neurones from the wing of Drosophila melanogaster arise from a small number of differentiated cell types which are localized in a precise and reproducible spatial pattern. We report here the distribution of the nerve pathways revealed by filling with peroxidase and the structure and number of the wing sensory receptors, in flies which have wings but which nevertheless are flightless, including one which presents abnormal wing formation. Our results indicate that in dumpy and taxi mutants, there are no detectable modifications in the neural projections or in the number and morphology of sensory receptors. Vestigial mutants however, present several alterations including the absence of the ovoid projection, a fact consistent with the existence of very few marginal bristles. The projection of the large companiform sensilla branch profusely along the ventromedial tract and more sensory fibers cross the midline in the mesothorax. Wings of vestigial mutants show a decrease in the number of large campaniform sensilla, and more importantly some receptors present abnormally oriented trichomes in the neighboring cells.