title: Expression patterns, mutation detection and RNA interference of Rhopalosiphum padi voltage-gated sodium channel genes.
abstract: The voltage-gated sodium channel (VGSC) is the target of sodium-channel-blocking insecticides. Traditionally, animals were thought to have only one VGSC gene comprising a α-subunit with four homologous domains (DI-DIV). The present study showed that Rhopalosiphum padi, an economically important crop pest, owned a unique heterodimeric VGSC (H1 and H2 subunits) encoded by two genes (Rpvgsc1 and Rpvgsc2), which is unusual in insects and other animals. The open reading frame (ORF) of Rpvgsc1 consisted 1150 amino acids, and the ORF of Rpvgsc2 had 957 amino acids. Rpvgsc1 showed 64.1% amino acid identity to DI-DII of Drosophila melanogaster VGSC and Rpvgsc2 showed 64.0% amino acid identity to DIII-DIV of D. melanogaster VGSC. A M918L mutation previously reported in pyrethroids-resistant strains of other insects was found in the IIS4-S6 region of R. padi field sample. The two R. padi VGSC genes were expressed at all developmental stages and showed similar expression patterns after treatment with beta-cypermethrin. Knockdown of Rpvgsc1 or Rpvgsc2 caused significant reduction in mortality rate of R. padi after exposure to beta-cypermethrin. These findings suggest that the two R. padi VGSC genes are both functional genes.
authors.affiliation: College of Plant Protection, Key Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, P.R. China.
authors.forename: Yayun
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: College of Plant Protection, Key Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, P.R. China.
authors.forename: Xiong
authors.initials: X
authors.lastname: Peng
authors.affiliation: College of Plant Protection, Key Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, P.R. China.
authors.forename: Kang
authors.initials: K
authors.lastname: Wang
authors.affiliation: College of Plant Protection, Key Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, P.R. China.
authors.forename: Fangfei
authors.initials: F
authors.lastname: Lin
authors.affiliation: College of Plant Protection, Key Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, P.R. China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Plant Protection, Key Laboratory of Crop Pest Integrated Pest Management on the Loess Plateau of Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, P.R. China.
authors.forename: Maohua
authors.initials: M
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001042:Aphids / Q000235:genetics*; D005786:Gene Expression Regulation; D007305:Insecticide Resistance / Q000235:genetics; D007306:Insecticides / Q000494:pharmacology; D015640:Ion Channel Gating; D009154:Mutation; D011722:Pyrethrins / Q000494:pharmacology; D034622:RNA Interference; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000737:chemistry / Q000235:genetics*
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D015222:Sodium Channels; C017160:cypermethrin