FIG. 1.

Characterization of dPDZ-GEF. (A) Schematic representation of the comparison between Drosophila and human PDZ-GEFs. Amino acid sequence identity is displayed as a percentage. (B) Expression of dPDZ-GEF in different developmental stages of Drosophila. E, embryo; 1st, first instar larva; 2nd, second instar larva; 3rd, third instar larva; P, pupa; F, adult female; M, adult male. A 600-bp fragment encompassing the central portion of dPDZ-GEF coding region was used as a probe. Arrowheads indicate 5.5- and 7.5-kb dPDZ-GEF message bands. 28S rRNA was shown as a control (bottom panel). (C) dPDZ-GEF transcription is dramatically abolished in the dPDZ-GEF¹ mutant. The quantities of dPDZ-GEF transcripts were visualized by RT-PCR experiments from the following samples: cloned dPDZ-GEF cDNA, adult Drosophila brain cDNA library, dPDZ-GEF¹/CyO Act-GFP (+/−) larvae, dPDZ-GEF¹/dPDZ-GEF¹ (−/−) larvae, and genomic DNA; rp49 transcripts were used as a control. Green fluorescent protein selection was performed under the fluorescent microscope at 30 h after egg laying to separate heterozygotes from homozygotes. (D) Genes near dPDZ-GEF are unaffected in the dPDZ-GEF¹ mutant. The expression profiles of dPDZ-GEF, Pez, Cpr, and CG9490, which are all the identified and/or predicted genes within 20 kb upstream and downstream of the dPDZ-GEF¹ insertion, were examined by RT-PCR in the heterozygotic (+/−) or homozygotic (−/−) presence of the dPDZ-GEF¹ allele. (E) Structure of the dPDZ-GEF locus. Open boxes indicate the coding sequence of the dPDZ-GEF gene, and breaks between the boxes indicate introns. The triangle represents the P-element insertion. dPDZ-GEF¹ and dPDZ-GEF² are dPDZ-GEF mutant alleles l(2)k13720 and EP(2)388, respectively.