title: Differential interactions of eyeless and twin of eyeless with the sine oculis enhancer.
abstract: Drosophila eye development is under the control of early eye specifying genes including eyeless (ey), twin of eyeless (toy), eyes absent (eya), dachshund (dac) and sine oculis (so). They are all conserved between vertebrates and insects and they interact in a combinatorial and hierarchical network to regulate each other expression. so has been shown to be directly regulated by ey through an eye-specific enhancer (so10). We further studied the regulation of this element and found that both Drosophila Pax6 proteins namely EY and TOY bind and positively regulate so10 expression through different binding sites. By targeted mutagenesis experiments, we disrupted these EY and TOY binding sites and studied their functional involvement in the so10 enhancer expression in the eye progenitor cells. We show a differential requirement for the EY and TOY binding sites in activating so10 during the different stages of eye development. Additionally, in a rescue experiment performed in the so(1) mutant, we show that the EY and TOY binding sites are required for compound eye and ocellus development respectively. Altogether, these results suggest a differential requirement for EY and TOY to specify the development of the two types of adult visual systems, namely the compound eye and the ocellus.
authors.affiliation: Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.
authors.forename: Claudio
authors.initials: C
authors.lastname: Punzo
authors.forename: Makiko
authors.initials: M
authors.lastname: Seimiya
authors.forename: Susanne
authors.initials: S
authors.lastname: Flister
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Gehring
authors.forename: Serge
authors.initials: S
authors.lastname: Plaza
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000378:metabolism; D004330:Drosophila / Q000254:growth & development*; D029721:Drosophila Proteins; D004742:Enhancer Elements, Genetic; D005123:Eye / Q000254:growth & development*; D005136:Eye Proteins / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D009024:Morphogenesis; D017956:Photoreceptor Cells, Invertebrate / Q000254:growth & development*; D011485:Protein Binding; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; C087345:So protein, Drosophila; D015534:Trans-Activators; C113278:ey protein, Drosophila; C118464:toy protein, Drosophila