title: RNA interference in marine and freshwater sponges: actin knockdown in Tethya wilhelma and Ephydatia muelleri by ingested dsRNA expressing bacteria.
abstract: BACKGROUND
  The marine sponge Tethya wilhelma and the freshwater sponge Ephydatia muelleri are emerging model organisms to study evolution, gene regulation, development, and physiology in non-bilaterian animal systems. Thus far, functional methods (i.e., loss or gain of function) for these organisms have not been available.
  
  
  RESULTS
  We show that soaking developing freshwater sponges in double-stranded RNA and/or feeding marine and freshwater sponges bacteria expressing double-stranded RNA can lead to RNA interference and reduction of targeted transcript levels. These methods, first utilized in C. elegans, have been adapted for the development and feeding style of easily cultured marine and freshwater poriferans. We demonstrate phenotypic changes result from 'knocking down' expression of the actin gene.
  
  
  CONCLUSIONS
  This technique provides an easy, efficient loss-of-function manipulation for developmental and gene regulatory studies in these important non-bilaterian animals.
authors.affiliation: Department of Biology, University of Richmond, Richmond, VA, USA.
authors.forename: Ajna S
authors.initials: AS
authors.lastname: Rivera
authors.forename: Jörg U
authors.initials: JU
authors.lastname: Hammel
authors.forename: Karri M
authors.initials: KM
authors.lastname: Haen
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Danka
authors.forename: Brandon
authors.initials: B
authors.lastname: Cieniewicz
authors.forename: Ian P
authors.initials: IP
authors.lastname: Winters
authors.forename: Dora
authors.initials: D
authors.lastname: Posfai
authors.forename: Gert
authors.initials: G
authors.lastname: Wörheide
authors.forename: Dennis V
authors.initials: DV
authors.lastname: Lavrov
authors.forename: Scott W
authors.initials: SW
authors.lastname: Knight
authors.forename: Malcolm S
authors.initials: MS
authors.lastname: Hill
authors.forename: April L
authors.initials: AL
authors.lastname: Hill
authors.forename: Michael
authors.initials: M
authors.lastname: Nickel
mesh_terms: D000199:Actins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D000818:Animals; D059001:Aquatic Organisms / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005247:Feeding Behavior; D005618:Fresh Water; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques / Q000379:methods*; D006651:Histocytochemistry; D018613:Microscopy, Confocal; D011161:Porifera / Q000166:cytology / Q000187:drug effects / Q000235:genetics*; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000008:administration & dosage / Q000096:biosynthesis / Q000235:genetics*; D012623:Seawater
chemical_list: D000199:Actins; D012330:RNA, Double-Stranded