A green fluorescent protein enhancer trap screen in Drosophila photoreceptor cells

The Drosophila ommatidia contain two classes of photoreceptor cells (PR's), the outer and the inner PR's. We performed an enhancer trap screen in orde r to target genes specifically expressed in PR's. Using the UAS/GAL4 method with enhanced green fluorescent protein (eGFP) as a vital marker, we scree ned 180 000 flies. Out of 2730 lines exhibiting new eGFP patterns, we focus ed on 16 lines expressing eGFP in particular subsets of PR's. In particular , we describe three lines inserted near the spalt major, m-spondin and furr owed genes, whose respective expression patterns resemble those genes. Thes e genes had not been reported to be expressed in the adult eye. These examp les clearly show the ability of our screen to target genes expressed in the adult Drosophila eye. (C) 2000 Elsevier Science Ireland Ltd. All rights re served.