飞蝗表皮鞣化关键基因laccase2的生物学功能及miRNA调控机制研究

The processof cuticular sclerotization or tanning plays an important role in the environmental adaptation and immunity of insects. Better understanding of the biological process and regulatory mechanism of cuticular tanning is of great significance to insect pest management. Laccase2 (Lac2) plays a key role in the insect tanning process. However, previous studies mainly focused on Lac2’s roles in developing body color and immunity. The roles of Lac2 on epidermal permeability and its miRNA regulatory mechanism have not been studied yet. In this proposed study, we aim to achieve the following scientific objectives using the migratory locust, Locusta migratoria, as an experimental model: 1) determining the biological influences of LmLac2 on body color, hardness, permeability by using RNAi; 2) revealing the effects of LmLac2 on ecological adaptability under environmental stresses including high temperature and fungal infection; 3) exploring potential regulatory mechanism of miRNA on LmLac2 by using a combined strategy of bioinformatic and molecular biology approaches. This work will help us to better understand the molecular mechanism of cuticular tanning in insects, clarify the relationship between the tanning process and insect ecological adaptability, and eventually provide important knowledge for developing novel and effective strategies for insect pest management.

昆虫表皮鞣化在环境适应及免疫应答等方面发挥着重要作用，解析昆虫表皮鞣化关键基因的生物学功能及调控机制对害虫科学防控具有重要意义。漆酶2（laccase2）在昆虫表皮鞣化过程中起着关键作用，然而，该基因对表皮通透性的影响及miRNA调控机制尚不明确，有待深入研究。本项目针对上述科学问题，以飞蝗为研究对象拟开展如下工作：1）采用RNAi技术沉默Lac2，从体色、硬度、通透性等方面系统解析其生物学功能；2）RNAi技术结合高温和真菌侵染等不同处理，研究Lac2对飞蝗生态适应性的影响；3）采用生物信息学及分子生物学技术，确定靶向调控飞蝗Lac2基因的潜在miRNA，探讨其参与飞蝗鞣化过程的作用机制。研究结果将有助于深入理解昆虫表皮鞣化的分子机制，明确鞣化与昆虫生态适应性的关系，为发展科学有效的害虫防控技术提供重要的理论依据。

飞蝗是重要的农业害虫，也是研究渐变态昆虫的模式物种之一。飞蝗一生经历卵、若虫和成虫3个发育阶段。由若虫发育到成虫需要经过5次蜕皮过程，每次蜕皮都需经历鞣化这一重要的生物过程使得表皮变黑变硬，从而使表皮可以行使其正确的生物学功能。因此解析飞蝗表皮鞣化关键基因的生物学功能及调控机制，可以作为设计生物防治靶标的重要依据。本研究结果显示，我们鉴定得到了在飞蝗鞣化过程中关键基因漆酶2（lac2）的全长序列，发现在表皮及蜕皮前高表达，通过RNA干扰实验证明lac2在飞蝗的鞣化中起到重要作用，并且发现lac2基因的下调会影响飞蝗对环境的适应性。这些结果以飞蝗为模式昆虫明确了鞣化与昆虫生态适应性的关系，为进一步发展科学有效的害虫防控技术提供重要的理论依据。