title: Systemic RNAi in the small hive beetle Aethina tumida Murray (Coleoptera: Nitidulidae), a serious pest of the European honey bee Apis mellifera.
abstract: BACKGROUND
  Aethina tumida is a serious pest of the European honey bee (Apis mellifera) in North America and Australia. Here we investigate whether Laccase 2, the phenoloxidase gene essential for cuticle sclerotisation and pigmentation in many insects, and vacuolar-ATPase V-type subunit A, vital for the generation of proton gradients used to drive a range of transport processes, could be potential targets for RNAi-mediated control of A. tumida.
  
  
  RESULTS
  Injection of V-ATPase subunit A (5 ng) and Laccase 2 (12.5 ng) dsRNAs resulted in 100% larval mortality, and qPCR confirmed significant decreases and enhanced suppression of transcript levels over time. Oral delivery of V-ATPase subunit A dsRNA in solutions resulted in 50% mortality; however, gene suppression could not be verified. We suggest that the inconsistent RNAi effect was a consequence of dsRNA degradation within the gut owing to the presence of extracellular nucleases. Target specificity was confirmed by a lack of effect on survival or gene expression in honey bees injected with A. tumida dsRNAs.
  
  
  CONCLUSIONS
  This is the first study to show evidence for systemic RNAi in A. tumida in response to injected dsRNA, but further research is required to develop methods to induce RNAi effects via ingestion. © 2016 Crown copyright. Pest Management Science © 2016 Society of Chemical Industry.
authors.affiliation: Fera Science Ltd, Sand Hutton, York, UK.|School of Biological and Biomedical Sciences, University of Durham, Durham, UK.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Powell
authors.affiliation: Fera Science Ltd, Sand Hutton, York, UK.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Bradish
authors.affiliation: School of Biological and Biomedical Sciences, University of Durham, Durham, UK.
authors.forename: John A
authors.initials: JA
authors.lastname: Gatehouse
authors.affiliation: Fera Science Ltd, Sand Hutton, York, UK.|School of Biological and Biomedical Sciences, University of Durham, Durham, UK.
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Fitches
mesh_terms: D000818:Animals; D001516:Bees / Q000469:parasitology; D001517:Coleoptera / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D042845:Laccase / Q000037:antagonists & inhibitors / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010572:Pest Control, Biological / Q000379:methods*; D034622:RNA Interference; D012330:RNA, Double-Stranded
chemical_list: D019476:Insect Proteins; D012330:RNA, Double-Stranded; D042845:Laccase
keywords: European honey bee (Apis mellifera); Laccase 2; V-ATPase subunit A; small hive beetle (Aethina tumida); systemic RNAi