title: Ingestion of bacterially expressed double-stranded RNA inhibits gene expression in planarians.
abstract: Freshwater planarian flatworms are capable of regenerating complete organisms from tiny fragments of their bodies; the basis for this regenerative prowess is an experimentally accessible stem cell population that is present in the adult planarian. The study of these organisms, classic experimental models for investigating metazoan regeneration, has been revitalized by the application of modern molecular biological approaches. The identification of thousands of unique planarian ESTs, coupled with large-scale whole-mount in situ hybridization screens, and the ability to inhibit planarian gene expression through double-stranded RNA-mediated genetic interference, provide a wealth of tools for studying the molecular mechanisms that regulate tissue regeneration and stem cell biology in these organisms. Here we show that, as in Caenorhabditis elegans, ingestion of bacterially expressed double-stranded RNA can inhibit gene expression in planarians. This inhibition persists throughout the process of regeneration, allowing phenotypes with disrupted regenerative patterning to be identified. These results pave the way for large-scale screens for genes involved in regenerative processes.
authors.affiliation: Department of Cell and Structural Biology, University of Illinois at Urbana-Champaign, B107 Chemical Life Sciences Laboratory, 601 South Goodwin Avenue, Urbana, IL 61801, USA. pnewmark@life.uiuc.edu
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Newmark
authors.forename: Peter W
authors.initials: PW
authors.lastname: Reddien
authors.forename: Francesc
authors.initials: F
authors.lastname: Cebrià
authors.forename: Alejandro
authors.initials: A
authors.lastname: Sánchez Alvarado
mesh_terms: D000818:Animals; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D008845:Microinjections; D010641:Phenotype; D010932:Planarians / Q000235:genetics* / Q000502:physiology*; D012313:RNA / Q000008:administration & dosage / Q000235:genetics; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000008:administration & dosage / Q000235:genetics*; D012038:Regeneration / Q000235:genetics
chemical_list: D012330:RNA, Double-Stranded; C039919:RNA, recombinant; D012313:RNA