title: Oral delivery of dsRNA lipoplexes to German cockroach protects dsRNA from degradation and induces RNAi response.
abstract: BACKGROUND
  In the past years, the concept of RNAi application for insect pest control has been proposed, considering the disruption of vital genes. However, the efficiency of RNAi is variable between different insect groups, especially by oral delivery of dsRNA. The purpose of this study is to assess the possibilities of RNAi as a tool for pest control using oral delivery of the dsRNAs encapsulated by liposome in the German cockroach Blattella germanica, which is highly sensitive to RNAi by injection of dsRNAs.
  
  
  RESULTS
  Injecting dsRNA into the abdomen of B. germanica caused dramatic depletion of essential α-tubulin gene and mortality. In contrast, oral delivery of the naked dsRNA resulted in lower RNAi efficiency, accounting for rapid degradation of the dsRNA in the midgut of B. germanica. Notably, we have further demonstrated that continuous ingestion of dsRNA lipoplexes in which dsRNA was encapsulated with a cationic liposome carrier was sufficient to slow down the degradation of dsRNA in the midgut and to increase the mortality of the German cockroach by significantly inhibiting α-tubulin expression in the midgut.
  
  
  CONCLUSIONS
  We provide empirical evidence that the formulation of dsRNA lipoplexes could be a plausible approach for insect pest control based on RNAi. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Entomology, National Taiwan University, Taipei, Taiwan.
authors.forename: Yu-Hsien
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Department of Entomology, National Taiwan University, Taipei, Taiwan.
authors.forename: Jia-Hsin
authors.initials: JH
authors.lastname: Huang
authors.affiliation: Department of Entomology, National Taiwan University, Taipei, Taiwan.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: CSIC-UPF, Institute of Evolutionary Biology, Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Belles
authors.affiliation: Department of Entomology, National Taiwan University, Taipei, Taiwan.
authors.forename: How-Jing
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001483:Base Sequence; D020048:Blattellidae / Q000235:genetics*; D004337:Drug Carriers / Q000737:chemistry*; D041981:Gastrointestinal Tract / Q000378:metabolism; D008081:Liposomes; D008297:Male; D034622:RNA Interference; D020871:RNA Stability; D012330:RNA, Double-Stranded / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D014404:Tubulin / Q000172:deficiency / Q000235:genetics
chemical_list: D004337:Drug Carriers; D008081:Liposomes; D012330:RNA, Double-Stranded; D014404:Tubulin
keywords: RNAi; liposome; pest control; ribonuclease; α-tubulin