This research will continue to examine axonal pathfinding in the developing wing of Drosophila by (1) identifying the ionic basis of the physiological difference by studying the neurons in a series of putative channel mutants; (2) by looking for the expression of the corresponding genes in the neurons using a variety of molecular probes given to us by the labs who have cloned the genes; (3) by testing the hypothesis that developmentally important hormones form the causal link between time of development, physiological behavior and choice of central pathway by growing the developing wings in vitro and manipulating the levels of 20-hydroxyecdysone and juvenile hormone. (4) Hormone manipulating results in a change in the number of cells that bind anti-HRP, the usual agent for identifying nerve cells in insects. In order to assess whether all the cells that develop under these conditions are neurons, the P.I. will apply multiple criteria of neural identity.
