lncRNA调控苹果蠹蛾抗病毒免疫的作用机制

Due to the extensive use of Cydia pomonella granulovirus (CpGV) in European countries, the codling moth (Cydia pomonella L.) has developed extremely high resistance to CpGV. To avoid the potential occurrence of high resistance when CpGV was used for controlling codling moth in China, it is of great importance to elucidate virus-host interaction and key regulatory factors. It has been demonstrated that long non-coding RNAs (lncRNAs) play an important role in diverse physiological processes in insects, such as growth, development and immune defense. This project is aimed at studying the regulatory role of lncRNA in virus-host interaction and the underlying mechanism. Based on the genome and transcriptome data of codling moth previously sequenced, bioinformatics and molecular biology techniques are employed to identify lncRNA genes showing specific response against virus infection. Additionally, the effects of key lncRNA on viral replication and host immune response to virus infection will be analyzed to unravel the role of lncRNA in the process of viral infection. Furthermore, multiple approaches such as in situ hybridization, RNA interference and RNA pull-down will be used to explore the molecular mechanism by which lncRNA regulates the antiviral immunity. It is anticipated that this study provides insights into the role of lncRNA during virus-host interaction and the molecular mechanism, advancing our understanding of insect antiviral immunity. Moreover, it provides important theoretical basis and technical support for improving the efficacy of granulovirus.

苹果蠹蛾颗粒体病毒在欧洲等国家的广泛使用，使得苹果蠹蛾产生了极高的抗性。为避免我国应用该病毒时苹果蠹蛾可能产生的高抗性问题，阐明病毒与宿主的相互作用及其调控因子至关重要。长链非编码RNA（lncRNA）在昆虫生长、发育、免疫防御等多种生理活动中发挥重要作用。本项目围绕“lncRNA在病毒与宿主互作中的调控作用与机制”这一科学问题，在前期完成的基因组、转录组等数据的基础上，拟采用生物信息学、分子生物学等技术手段，筛选特异性响应病毒感染的lncRNA基因；通过对病毒复制过程和宿主免疫应答的分析，明确lncRNA基因在病毒感染中的功能；采用原位杂交、RNA干扰、RNA pull-down等实验方法探索lncRNA调控宿主抗病毒免疫的作用机制。本研究结果有助于揭示lncRNA在病毒与宿主免疫互作中的作用与分子机制，丰富昆虫抗病毒免疫相关理论，为改善颗粒体病毒的防治效果提供重要的理论基础和技术支持。

苹果蠹蛾是我国重点管控的外来入侵害虫，严重危害仁果类水果生产安全。在欧洲等国家，由于颗粒体病毒制剂的长期使用造成苹果蠹蛾田间种群对病毒产生了高倍抗性。为了深入理解宿主昆虫与颗粒体病毒的相互作用，以及为恢复病毒制剂田间防效寻找潜在靶标，本项目通过颗粒体病毒侵染前后的lncRNA测序，构建了首个苹果蠹蛾全基因组水平的lncRNA数据集，挖掘病毒侵染前后差异表达的lncRNA及靶标基因，分析lncRNA对宿主免疫应答的影响和调控作用，获得以下研究结果：. 1.基于基因组和转录组数据，构建了苹果蠹蛾lncRNA基因集并解析其基因组特征。比较发现，lncRNA具有较短的序列、较低的GC含量和表达水平。此外，lncRNA具有更强的组织特异性，部分lncRNA在精巢中偏好性表达。保守性分析表明，lncRNA在物种间序列相似性水平很低，基于共线关系可鉴定到更多同源关系的lncRNA。lncRNA同邻近编码基因具有很强相关性，表明lncRNA可能调控邻近基因表达。. 2.基于病毒侵染后4个时间点的测序数据，揭示了颗粒体病毒基因的表达动力学特征，明确了不同类别基因的表达时相，发现侵染后48h为病毒感染的重要时间节点。. 3.明确了病毒侵染后宿主基因的响应模式和特征：lncRNA和编码基因对于病毒侵染的响应模式存在很大差异。上调基因主要与组蛋白修饰、免疫反应、细胞自噬和细胞周期调控等生物学过程有关，显著富集在Toll和Imd等免疫信号通路；下调基因则主要与糖代谢和能量代谢过程相关，表明病毒侵染显著调控宿主免疫防御反应和代谢水平。. 4.明确了苹果蠹蛾响应病毒侵染的lncRNA与mRNA的共表达网络：通过荧光定量PCR验证了差异lncRNA的表达，共表达的编码基因涉及多个昆虫免疫相关基因，包括几个丝氨酸蛋白酶抑制剂serpin基因。病毒侵染可能通过lncRNA调控serpin基因的表达水平，抑制宿主的黑化反应等抗病毒免疫反应，从而有利于病毒自身的繁殖和复制。. 本项目加深了我们对于苹果蠹蛾与病毒互作的理解和认识，有助于推动苹果蠹蛾生防制剂的研发和改良。