The wing of Drosophila is a relatively simple but highly ordered tissue. It contains a limited number of histologically identifiable cell types arranged into a precise pattern of structures. The decision to form a particular cell type is made for the most part during the latter stages of the growth of the wing imaginal disc and Dr. Blair is examining the mechanisms underlying these events. He here proposes to look at the problem of patterned formation of wing veins. The specific aims are as follows: 1) To isolate and characterize cell-specific vein markers which will allow him to follow the process of vein formation in detail; screening known genes as well as new enhancer trap lines, has already led to the isolation of markers which are specific for preveins, mature veins, and the posterior cross vein, 2) To use these markers to follow the effects of different classes of venation mutations during development. Newly developed techniques will allow an investigation of the effects of both viable and embryonic lethal mutations and future studies will also make use of techniques for the localized over expression of genes. The purpose of these studies is to identify critical steps in the venation process and the genes required for each. Also addressed will be issues of cell autonomy of such mutations and the roles played by genes during the cell- cell interactions critical to the patterning process, 3) To initiate the genetic and molecular characterization of novel and previously characterized vein-pattern genes, and 4) To perform surgical manipulations to the disc in order to better understand the cell-cell interactions required for vein patterning.
