Genetic suppression of putative guidepost cells: effect on establishment of nerve pathways in Drosophila wings.

In the developing wing of Drosophila a set of early differentiating neurons pioneer the axon courses observed in the adult. The possibility that these first cells are indispensable for establishing the normal neural pathways has been tested. The differentiation of particular neurons was suppressed by inducing cell clones homozygous for two scute deficiencies, mutations that inhibit the differentiation of sensilla and their associated neurons. From the analysis of the nerve patterns in wings lacking specific sensilla, it has been demonstrated that none of the identified neurons are essential for guiding other axons along the correct path. However, the possibility remains that the presence of certain cells may increase the probability of establishing the normal pattern of peripheral nerves.