VISUALIZATION OF GENE-EXPRESSION IN LIVING ADULT DROSOPHILA

To identify genes involved in the patterning of adult structures, Ga14 -UAS (upstream activating site) technology was used to visualize patte rns of gene expression directly in living flies. A large number of Ga1 4 insertion lines were generated and their expression patterns were st udied. In addition to identifying several characterized developmental genes, the approach revealed previously unsuspected genetic subdivisio ns of the thorax, which may control the disposition of pattern element s. The boundary between two of these domains coincides with localized expression of the signaling molecule wingless.