title: An RNAi Screen for Genes Involved in Nanoscale Protrusion Formation on Corneal Lens in Drosophila melanogaster.
abstract: The "moth-eye" structure, which is observed on the surface of corneal lens in several insects, supports anti-reflective and self-cleaning functions due to nanoscale protrusions known as corneal nipples. Although the morphology and function of the "moth-eye" structure, are relatively well studied, the mechanism of protrusion formation from cell-secreted substances is unknown. In Drosophila melanogaster, a compound eye consists of approximately 800 facets, the surface of which is formed by the corneal lens with nanoscale protrusions. In the present study, we sought to identify genes involved in "moth-eye" structure, formation in order to elucidate the developmental mechanism of the protrusions in Drosophila. We re-examined the aberrant patterns in classical glossy-eye mutants by scanning electron microscope and classified the aberrant patterns into groups. Next, we screened genes encoding putative structural cuticular proteins and genes involved in cuticular formation using eye specific RNAi silencing methods combined with the Gal4/UAS expression system. We identified 12 of 100 candidate genes, such as cuticular proteins family genes (Cuticular protein 23B and Cuticular protein 49Ah), cuticle secretion-related genes (Syntaxin 1A and Sec61 ββ subunit), ecdysone signaling and biosynthesis-related genes (Ecdysone receptor, Blimp-1, and shroud), and genes involved in cell polarity/cell architecture (Actin 5C, shotgun, armadillo, discs large1, and coracle). Although some of the genes we identified may affect corneal protrusion formation indirectly through general patterning defects in eye formation, these initial findings have encouraged us to more systematically explore the precise mechanisms underlying the formation of nanoscale protrusions in Drosophila.
authors.affiliation: 1 Laboratory of Biology, Hokkaido University of Education, Sapporo Campus, Sapporo 002-8502, Japan.
authors.forename: Ryunosuke
authors.initials: R
authors.lastname: Minami
authors.affiliation: 1 Laboratory of Biology, Hokkaido University of Education, Sapporo Campus, Sapporo 002-8502, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Sato
authors.affiliation: 2 Department of Biology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Yamahama
authors.affiliation: 3 Department of Mathematics, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Kubo
authors.affiliation: 2 Department of Biology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Hariyama
authors.affiliation: 1 Laboratory of Biology, Hokkaido University of Education, Sapporo Campus, Sapporo 002-8502, Japan.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Kimura
mesh_terms: D000818:Animals; D003315:Cornea / Q000648:ultrastructure*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D049329:Nanostructures / Q000648:ultrastructure; D055620:Optical Phenomena; D034622:RNA Interference; D013499:Surface Properties
chemical_list: D029721:Drosophila Proteins
keywords: Drosophila melanogaster; RNAi screening; biomimetics; corneal protrusion; cuticle; nanostructure; “moth-eye” structure