miR-9b调控生物胁迫因子诱导的褐色桔蚜翅型分化的分子机制

Wing dimorphism functions as an adaptive switch to environmental changes that winged morphs obtained the flight capability to escape unfavorable conditions and to migrate to new suitable habitats. However, as a key critical component of post-transcriptional gene expression regulation, whether miRNA involved in biotic stressors mediated wing dimorphism and the molecular mechanism is still unclear. Here, The main vector of Citrus tristeza virus, Aphis citricidus, is used to focus on the molecular mechanism of miR-9b regulated various biotic stressors-mediated wing dimorphism of the aphid. Many technologies such as in situ hybridization, Dual-Glo luciferase report system and RNA interference are using to point out the targeted relationship between miR-9b and ABCG4; the expression patterns of miR-9b in response to various biotic stressors is investigated; the mechanism of miR-9b mediated activating of insulin pathway and glucose/lipid metabolism are analyzing and finally clarifying the molecular mechanism of miR-9b regulated wing dimorphism in A. citricidus. The results are useful to understand the wing dimorphism of insects and also promote to find the novel small RNA target as an insecticide as well as provide a new control strategy on the aphid pests. Therefore, it has important theoretical significance and application prospects.

翅型分化是昆虫对不良栖息环境的适应，昆虫通过提高飞行能力逃离不良环境并寻获新的栖息地。然而，miRNA作为重要的后转录调控因子，是否介导生物胁迫因子诱导的昆虫翅型分化及其调控机制仍不明确。本项目以柑桔衰退病毒的主要传播媒介褐色桔蚜Aphis citricidus为研究对象，紧密围绕miR-9b调控生物胁迫因子诱导的褐色桔蚜翅型分化的分子机制这一关键科学问题，系统运用原位杂交、双荧光素酶报告系统、RNA干扰等技术明确褐色桔蚜miR-9b对ABCG4的靶向调控机制、解析miR-9b响应生物胁迫因子的表达模式、阐明miR-9b对胰岛素信号通路活性及糖脂代谢的调控和对翅型分化的影响，最终揭示miR-9b调控褐色桔蚜翅型分化的分子机制。研究结果不仅有助于解析翅二型昆虫翅型分化调控机理，还有利于寻获新的小分子RNA控制剂靶标，为蚜虫类害虫防控提供新的思路。因此，具有重要的理论意义和应用前景。

翅型分化是蚜虫对不良栖息环境的适应，蚜虫通过提高飞行能力使其逃离不良环境并找到新的栖息地，翅型分化现象作为蚜虫重要的生态对策与其爆发成灾及传播病毒密切相关。因此，明确翅型分化的分子调控机制，对蚜虫的持续控制具有重要的理论和实践意义。本研究以褐色桔蚜Aphis citricidus为研究对象，首先利用高通量测序手段，构建环境因子诱导的褐色桔蚜翅型分化非编码RNA和转录组数据库，筛选鉴定出褐色桔蚜翅型分化相关的非编码RNA；随后利用靶基因预测软件、饲喂miRNAs类似物和抑制剂、miRNA-靶基因表达模式解析、双荧光素酶报告系统以及RNA结合蛋白免疫沉淀确定aci-miR-9b对ABC转运蛋白的靶向调控作用；利用活体饲喂miRNA类似物/抑制剂/dsRNA的方法明确miR-9b对褐色桔蚜翅型分化的影响；最后通过对糖脂物质含量的影响、对胰岛素信号通路活性的调控以及胰岛素信号通路关键基因的干扰揭示miR-9b调控蚜虫翅型分化的分子机制。本研究结果为揭示蚜虫翅型分化、迁飞扩散、以及研发新型控制剂作用靶点奠定理论基础。