Identification and Expression of Inward-Rectifying Potassium Channel Subunits in Plutella xylostella

Abstract

In insects, inward-rectifying potassium (Kir) channels regulate vital physiological functions, such as feeding behavior, silk secretion, renal excretion, and immune function. Therefore, they offer promising potential as targets for insecticides. Three types of Kir subunits have been identified in Diptera and Hemiptera, but the Kir subunits of Lepidoptera still remain unclear. This study identified five Kir subunit genes (pxkir1, pxkir2, pxkir3A, pxkir3B, and pxkir4) in the transcriptome of Plutella xylostella. Phylogenetic analysis identified pxkir1, pxkir2, pxkir3A, and pxkir3B as orthologous genes of kir1–3 in other insects. Interestingly, pxkir4 may be encoding a new class of Kir subunit in Lepidoptera that has not been reported to date. To identify further Kir channel subunits of P. xylostella, the gene expression profiles of five pxkir genes were studied by quantitative real-time PCR. These pxkir genes are expressed throughout the development of P. xylostella. pxkir1 and pxkir2 were highly expressed in thoraxes and legs, while pxkir3 (3A and 3B) and pxkir4 had high expression levels in the midgut and Malpighian tubules. This study identified the composition and distribution of Kir subunits in P. xylostella for the first time, and provides useful information for the further study of Kir channel subunits in Lepidoptera.

Phenyl imidazolidin‐2‐ones antagonize a β‐adrenergic‐like octopamine receptor in diamondback moth (Plutella xylostella)

“…The biological results of three replicates were analyzed, and the relative gene expression levels were calculated via the comparative CT (2 −ΔΔCT ) method. 34 2.6 Cell culture, transfection, and Ca 2+ imaging HEK-293 T cells were seeded on 60 mm glass-bottom Petri dishes (Sigma-Aldrich), and allowed to reach a confluence of approximately 70-90%. Cells were transiently transfected with 2 μg of PxOA2B1-expressing plasmid and G⊍16-expressing plasmid by Lipofectamine® 2000 (Invitrogen), following the manufacturer's instructions.…”

Phylogenomics of Tick Inward Rectifier Potassium Channels and Their Potential as Targets to Innovate Control Technologies

“…However, the aphids Acyrthosiphon pisum and Aphis glycines have only two (Kir1 and Kir2), suggesting a loss of Kir3 during aphid evolution ( Piermarini et al., 2018 ). A recent study of Kir channels revealed a possible fourth subtype in Lepidoptera (Kir4), which was not found in the Diptera, Heteroptera, and Homoptera included in the study ( Lai et al., 2020 ).…”

“…Compared to mammals, insects possess a smaller repertoire of Kir channels, ranging in number from three to six genes in the species studied thus far ( Lai et al., 2020 ). Based on phylogenetic analysis, there are at least three different subtypes of insect Kir channels.…”

AC–DC electropenetrography: fundamentals, controversies, and perspectives for arthropod pest management

“…130,131 The latter compound, pymetrozine, blocks the transient receptor potential vanilloid (TRPV) channels of chordotonal organs, thus directly and selectively interfering with feeding behavior of sap-feeding insects, leading to their starvation. 132,133 By contrast, flonicamid inhibits inward rectifier potassium (Kir) channels of epithelial and glandular systems, compromising salivary activity and fluid-feeding. 134,135 Arthropod pest management impacts of EPG for contact insecticides include and go beyond sap-feeding insects, although other insects have been largely neglected.…”

“…The antifeedant and growth regulator azadirachtin was one of the earliest targets of EPG research in aphids and leafhoppers, 111,129 along with flonicamid and pymetrozine in aphids, leafhoppers, and psyllids 130,131 . The latter compound, pymetrozine, blocks the transient receptor potential vanilloid (TRPV) channels of chordotonal organs, thus directly and selectively interfering with feeding behavior of sap‐feeding insects, leading to their starvation 132,133 . By contrast, flonicamid inhibits inward rectifier potassium (Kir) channels of epithelial and glandular systems, compromising salivary activity and fluid‐feeding 134,135 …”