Molecular characterization and expression pattern of three GABA receptor-like subunits in the small brown planthopper Laodelphax striatellus (Hemiptera: Delphacidae)

Pestic Biochem Physiol. 2017 Mar;136:34-40. doi: 10.1016/j.pestbp.2016.08.007. Epub 2016 Aug 24.

Abstract

Ionotropic γ-aminobutyric acid (GABA)-gated chloride channel receptors mediate rapid inhibitory neurotransmission in vertebrates and invertebrates. GABA receptors are well known to be the molecular targets of synthetic insecticides or parasiticides. Three GABA receptor-like subunits, LsLCCH3, LsGRD and LS8916, of the small brown planthopper, Laodelphax striatellus (Fallén), a major insect pest of crop systems in East Asia, had been identified and characterized in this study. All three genes were cloned using the reverse transcriptase polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). They shared common structural features with known Cys-loop ligand-gated ion channels (LGICs): the well-conserved dicysteine-loop structures, an extracellular N-terminal domain containing six distinct regions (loops A-F) that form the ligand binding sites and four transmembrane regions (TM1-4). Additionally, temporal and spatial transcriptional profiling analysis indicated that Lslcch3 was significantly higher than the other two genes. All of them were expressed at higher levels in fifth-instar nymph and adults than in eggs and from first- to fourth-instar nymph. They were predominantly expressed in the heads of 2-d old female adults. These findings enhanced our understanding of cys-loop LGIC functional characterization in Hemiptera and provided a useful basis for the development of improved insecticides that targeting this important agricultural pest.

Keywords: GABA receptor-like subunit; Insecticide target; Laodelphax striatellus; Ligand-gated ion channel; mRNA expression.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Female
  • Hemiptera / genetics*
  • Insect Proteins / genetics*
  • Male
  • Phylogeny
  • Protein Subunits / genetics*
  • RNA, Messenger / metabolism
  • Receptors, GABA / genetics*
  • Sequence Analysis, DNA

Substances

  • DNA, Complementary
  • Insect Proteins
  • Protein Subunits
  • RNA, Messenger
  • Receptors, GABA