title: Regulation of twin of eyeless during Drosophila development.
abstract: The Pax-6 protein is vital for eye development in all seeing animals, from sea urchins to humans. Either of the Pax6 genes in Drosophila (twin of eyeless and eyeless) can induce a gene cascade leading to formation of entire eyes when expressed ectopically. The twin of eyeless (toy) gene in Drosophila is expressed in the anterior region of the early fly embryo. At later stages it is expressed in the brain, ventral nerve cord and (eventually) the visual primordium that gives rise to the eye-antennal imaginal discs of the larvae. These discs subsequently form the major part of the adult head, including compound eyes. We have searched for genes that are required for normal toy expression in the early embryo to elucidate initiating events of eye organogenesis. Candidate genes identified by mutation analyses were subjected to further knock-out and miss-expression tests to investigate their interactions with toy. Our results indicate that the head-specific gap gene empty spiracles can act as a repressor of Toy, while ocelliless (oc) and spalt major (salm) appear to act as positive regulators of toy gene expression.
authors.affiliation: Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden.
authors.forename: John
authors.initials: J
authors.lastname: Skottheim Honn
authors.affiliation: Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden.
authors.forename: Linn
authors.initials: L
authors.lastname: Johansson
authors.affiliation: Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden. Electronic address: asa.rasmuson-lestander@umu.se.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Rasmuson Lestander
mesh_terms: D000818:Animals; D001921:Brain / Q000254:growth & development / Q000378:metabolism; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D005123:Eye / Q000254:growth & development* / Q000378:metabolism; D005136:Eye Proteins / Q000096:biosynthesis / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D055786:Gene Knockout Techniques; D018398:Homeodomain Proteins / Q000235:genetics*; D060227:Imaginal Discs / Q000254:growth & development / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000254:growth & development; D009154:Mutation; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D029721:Drosophila Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C093053:oc protein, Drosophila; C085793:salm protein, Drosophila; C118464:toy protein, Drosophila
keywords: Drosophila melanogaster; Eye development; Pax6; twin of eyeless