Southern blot analysis. Genomic DNA from D. melanogasterCanton S. was digested with one of five restrictions enzymes (BamHI, EcoRV, SacI, SalI, andXbaI). After electrophoresis and blotting, the genomic fragments were hybridized with a cDNA fragment coding for the Leu-rich repeats 10–18 and the transmembrane domain of DLGR-2. The size of the markers (left) is in kb. All lanes show a single hybridization band with exception of the lane containing the XbaI fragment.