番石榴实蝇全触角神经纤维束及其投射的示踪研究

Sensory nerve fibers of different modalities in the antenna form a close connection with the antennal lobe (AL) and antennal mechanosensory and motor center (AMMC) in the insect brain, which is the neural basis for insects to process environmental information and locate the host plants. However, the spatial distribution characteristics of each modality nerve bundle and its pathway from the antenna to the brain are still unclear. Guava fruit fly is a harmful insect that invaded our country at the end of the last century. It is an important pest of economic fruits such as mango and guava in Yunnan. In this project, based on our improved nickel chloride and cobalt chloride neural tracer technology, we carried out the observation of the transparency of the whole antenna, discriminating the number of nerve bundles and their spatial distribution, and their projections in the brain. Using immunofluorescence antibodies and three-dimensional reconstruction techniques, the antennal lobes were traced and analyzed. Based on scanning electron microscopy, the types of sensilla on the surface of the antennae and their spatial distribution characteristics were studied. This study will be the first to achieve visualization of the whole antennal nerve fiber bundles, and to obtain the spatial distribution map of the world's first intact antenna and longest distance nerve fiber bundles. This will provide basic information for relevant in-depth studies,and also provide the basis for developing pest environmental friendly control technology.

触角不同模态的神经纤维束与脑建立了紧密的联接，形成了不同的初级感觉神经通路。它是昆虫处理不同环境信息，对寄主植物进行搜索、导航定位的神经基础。但迄今，触角的各模态神经纤维束的空间分布及其通路特征基本不清楚。番石榴实蝇是上世纪末入侵我国的有害昆虫，是云南重要经济类水果芒果、番石榴等的重要害虫。本项目拟以番石榴实蝇为材料，基于我们改进的氯化镍和氯化钴神经示踪技术，国际上首次在不切片的条件下进行全触角透视化观察，原位辨析神经束数量、空间分布、路径及其投射；利用免疫荧光抗体及三维重构技术，分析触角神经的主要投射区触角叶的形态结构；基于扫描电镜技术，研究触角表面的感器种类及空间分布特征，进而初步探讨各神经束的可能功能。该研究将是首次实现全触角的神经纤维束可视化，获得世界首张全触角、最长距离（超过1300μm）的神经纤维束空间分布及投射图。该结果将为进一步深入研究感觉机制和发展害虫绿色防控技术奠定基础

昆虫主要依赖触角探测、捕捉和感知外部的环境信息。昆虫触角角质层内部的不同模态的神经纤维束进一步与脑建立了紧密的联接，形成了不同的初级感觉神经通路。它是昆虫处理不同环境信息，对寄主植物进行搜索、导航定位的神经基础。但迄今，由于各种技术的限制，不透明触角内部的神经纤维束的空间分布及其通路特征基本不清楚。另外一方面，许许多多实蝇科昆虫是我国和世界的重大入侵害虫。包括橘小实蝇、番石榴实蝇。它们侵害重要经济类水果芒果、番石榴等，产生了重要经济影响。本项目以番石榴实蝇为材料，基于我们改进的氯化镍和氯化钴神经示踪技术，国际上首次在不切片的条件下进行全触角透视化观察，原位辨析神经束数量、空间分布、路径；利用各种技术，分析触角神经的主要投射区及其特征；基于扫描电镜技术，研究触角表面的感器种类及空间分布特征，进而为探讨各神经束的可能功能奠定基础。我们首次实现全触角的透视化以及触角神经纤维束的可视化追踪技术；获得世界首张全触角、最长距离（1300μm）的神经纤维束空间分布及投射图谱；获得了不透明触角内部神经束的空间分布及其路径等综合信息。该结果对昆虫解剖学研究有重要的意义，促进对昆虫的透视化研究；将为进一步深入研究昆虫感觉机制创造新条件，为全面了解触角的作用方式创造新条件，也为开发害虫防治新技术提供重要的进一步理论基础。总之，该项目选题新颖，独辟蹊径，设计巧妙，结果清晰。