Chen Dongxu, Hawthorne David J
Department of Entomology, Plant Science Building, University of Maryland, College Park, MD, 20740, USA.
BMC Genomics. 2025 Jul 29;26(1):702. doi: 10.1186/s12864-025-11867-5.
The insect cys-loop ligand-gated ion channel (cysLGIC) superfamily includes nicotinic acetylcholine receptors (nAChRs), γ-aminobutyric acid (GABA) receptors, glutamate- or histamine-gated chloride channels (GluCls and HisCls), pH-sensitive chloride channels (pHCls) and several other functionally uncharacterized receptors. Several of these receptors are target sites of neonicotinoids and other insecticides. Characterizing sequences of cysLGIC genes can facilitate the study of functional expression of subunits allowing insecticide/receptor interaction research, provide candidate targets for RNAi interventions, and can promote molecular resistance monitoring tools development. The Colorado potato beetle (CPB) is an agricultural pest that threatens the production of solanaceous crops. Although this insect shows frequent evolution of insecticide resistance, its cysLGIC superfamily is not well characterized.
Twenty-two candidate CPB cysLGIC subunit genes were identified, and the functional regions of their protein sequences were annotated. CPB possesses twenty-two candidate cysLGIC subunit genes such as nAChR α4, nAChR α6, Rdl, and GluCl subunits, with similar sequence, structure, and alternative exon use as that of other insects. RNA A-to-I editing was observed of nAChR α6. Two copies of the pHCl subunit gene were identified, the first duplication of this gene observed in insects.
The number of cysLGIC superfamily genes is similar to that of other insect species. Alternative splicing and RNA editing conserved in insect species were also identified in expected subunits, potentially contributing to structural and functional diversity of the receptor. Evidence of naturally truncated nAChR α4 and duplicated pHCl was observed, which invites future validation.
昆虫半胱氨酸环配体门控离子通道（cysLGIC）超家族包括烟碱型乙酰胆碱受体（nAChRs）、γ-氨基丁酸（GABA）受体、谷氨酸或组胺门控氯离子通道（GluCls和HisCls）、pH敏感氯离子通道（pHCls）以及其他一些功能未明确的受体。这些受体中的几种是新烟碱类和其他杀虫剂的作用靶点。表征cysLGIC基因序列有助于研究亚基的功能表达，从而进行杀虫剂/受体相互作用研究，为RNAi干预提供候选靶点，并可促进分子抗性监测工具的开发。科罗拉多马铃薯甲虫（CPB）是一种威胁茄科作物生产的农业害虫。尽管这种昆虫经常出现抗药性进化，但其cysLGIC超家族尚未得到充分表征。
鉴定出22个候选CPB cysLGIC亚基基因，并对其蛋白质序列的功能区域进行了注释。CPB拥有22个候选cysLGIC亚基基因，如nAChR α4、nAChR α6、Rdl和GluCl亚基，其序列、结构和外显子使用方式与其他昆虫相似。观察到nAChR α6存在RNA A到I编辑。鉴定出两个pHCl亚基基因拷贝，这是在昆虫中首次观察到该基因的重复。
cysLGIC超家族基因的数量与其他昆虫物种相似。在预期的亚基中也发现了昆虫物种中保守的可变剪接和RNA编辑，这可能有助于受体的结构和功能多样性。观察到天然截短型nAChR α4和重复的pHCl的证据，有待进一步验证。
