title: Conditional knockout of retinal determination genes in differentiating cells in Drosophila.
abstract: Conditional gene knockout in postmitotic cells is a valuable technique which allows the study of gene function with spatiotemporal control. Surprisingly, in contrast to its long-term and extensive use in mouse studies, this technology is lacking in Drosophila. Here, we use a novel method for generating complete loss of eyes absent (eya) or sine oculis (so) function in postmitotic cells posterior to the morphogenetic furrow (MF). Specifically, genomic rescue constructs with flippase recognition target (FRT) sequences flanking essential exons are used to generate conditional null alleles. By removing gene function in differentiating cells, we show that eya and so are dispensable for larval photoreceptor differentiation, but are required for differentiation during pupal development. Both eya and so are necessary for photoreceptor survival and the apoptosis caused by loss of eya or so function is likely a secondary consequence of inappropriate differentiation. We also confirm their requirement for cone cell development and reveal a novel role in interommatidial bristle (IOB) formation. In addition, so is required for normal eye disc morphology. This is the first report of a knockout method to study eya and so function in postmitotic cells. This technology will open the door to a large array of new functional studies in virtually any tissue and at any stage of development or in adults.
authors.affiliation: Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Jin
authors.affiliation: Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA.|Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Aiden
authors.initials: A
authors.lastname: Eblimit
authors.affiliation: Department of Surgery, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Merlyn
authors.initials: M
authors.lastname: Pulikkathara
authors.affiliation: Department of Surgery, Baylor College of Medicine, Houston, TX, USA.|Department of Chemistry, Rice University, Houston, TX, USA.|Department of Biomedical Engineering, University of Houston, TX, USA.
authors.forename: Stuart
authors.initials: S
authors.lastname: Corr
authors.affiliation: Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA.|Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.|Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.affiliation: Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA.|Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.|Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA.|Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.|Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.|Program in Cell and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Graeme
authors.identifier: 0000-0003-4265-4072
authors.initials: G
authors.lastname: Mardon
mesh_terms: D000483:Alleles; D000818:Animals; D002454:Cell Differentiation; D004330:Drosophila / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D005123:Eye / Q000033:anatomy & histology / Q000254:growth & development / Q000648:ultrastructure; D005136:Eye Proteins / Q000235:genetics / Q000502:physiology*; D055786:Gene Knockout Techniques; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D007814:Larva / Q000166:cytology; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology*; D012160:Retina / Q000254:growth & development
chemical_list: D029721:Drosophila Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; C087345:So protein, Drosophila; C092694:eya protein, Drosophila
keywords: Drosophila; conditional gene knockout; eye development; eyes absent; sine oculis