GREEN FLUORESCENT PROTEIN AS A VITAL MARKER AND REPORTER OF GENE-EXPRESSION IN DROSOPHILA

We have used the green fluorescent protein (GFP) from the jellyfish Ae quorea victoria as a vital marker/reporter in Drosophila melanogaster. Transgenic flies were generated in which GFP was expressed under the transcriptional control of the yeast upstream activating sequence that is recognized by GAL4. These flies were crossed to several GAL4 enhan cer trap lines, and expression of GFP was monitored in a variety of ti ssues during development using confocal microscopy. Here, we show that GFP could be detected in freshly dissected ovaries, imaginal discs, a nd the larval nervous system without prior fixation or the addition of substrates or antibodies. We also show that expression of GFP could b e monitored in intact living embryos and larvae and in cultured egg ch ambers, allowing us to visualize dynamic changes in gene expression du ring real time.