南方根结线虫3个AChE基因功能研究

Acetylcholinesterase (AChE, EC 3.1.1.7) plays a critical role in terminating nerve impulses by hydrolyzing the neurotransmitter, acetylcholine (ACh) in the cholinergic nervous system of most animals. AChE is also reported to be distributed in a variety of non-neuronal tissues. AChE is the target for the action of organophosphate (OP) and carbamate (CB) pesticides. .Unlike vertebrates and insects, nematodes have at least three or four AChE genes encoding different AChE types (ACE-1, ACE-2, ACE-3 and ACE-4). Each AChE showed different pharmacological properties and localization pattern in tissue and cells, suggesting their multiple functions. Caenorhabditis elegans has been widely studied as a model for nematode acetylcholinesterases. Acetylcholinesterases from free-living C. elegans, however, may not be a good model to study the properties of acetylcholinesterases from plant-parasitic nematodes, particularly the root-knot nematode, which has adapted to host. .In our previous study, three AChE genes (Miace-1，Miace-2 and Miace-3) were identified from the root-knot nematode Meloidogyne incognita. The relative transcript level of each Miace according to different life stages (eggs, infective juvenile and females) was analyzed by using quantitative PCR (qPCR). The results revealed that the transcript levels of all three Miaces were higher in infective juveniles than other stages, suggesting that AChE genes play a critical role in infective juveniles growth and development. To date, the functional boundary of nematode acetylcholinesterases has not yet been clari?ed. There has been scant information on which of the three AChE genes is responsible for cholinergic neurotransmission and therefore a target of anticholinesterase insecticides. The function of AChE genes from root-knot nematodes is not clear..In this study, we try to investigate the three AChE genes (Miace-1，Miace-2 and Miace-3) tissue distribution patterns via in-situ hybridization, and explore functional differences of the three AChE genes by using RNA interference(RNAi) experiments, so as to further understand the biological function of three AChE genes from the root-knot nematode. Our studies on AChE genes from a plant-parasitic nematode species will provide valuable insights into the various biological functions of acetylcholinesterase. Furthermore, a better understanding of the properties of AChE genes will be pertinent for developing OP- or CB-based synergists and alternative novel nematicides against root knot nematodes. Our studies will also provide a scientific basis for developing novel plant parasite nematodes control strategies.

乙酰胆碱酯酶（AChE）在神经传导和生物发育中具有重要的作用，是有机磷和氨基甲酸酯类农药的主要作用靶标。我们前期从南方根结线虫克隆了3个AChE基因Miace-1、Miace-2和Miace-3，这是首次从根结线虫上获得ace-3，进一步证实了线虫中至少存在3种AChE基因。但这3个基因中，究竟哪一个具有"经典"的类胆碱神经元功能，是杀虫剂的主要作用靶标？是否有基因具有"非经典"的功能，调控线虫发育或繁殖？目前尚不清楚。.本项目拟在现有工作基础上，对这3个基因进行深入研究。通过原位杂交分析它们的组织表达特性；通过dsRNA浸泡的离体RNAi技术结合植物介导的RNAi技术，分别干涉侵染前和侵染后线虫，分析对线虫生长发育影响，及不同AChE基因受抑制后，线虫对杀线剂敏感性差异，以期了解这3个的基因功能，为利用RNAi技术防治根结线虫这一新的策略及线虫抗药性治理和开发高选择性杀线剂提供理论依据

乙酰胆碱酯酶（AChE）在神经传导和生物发育中具有重要的作用，是有机磷和氨基甲酸酯类农药的主要作用靶标。本项目对这3个基因进行深入研究。通过原位杂交分析它们的组织表达特性；植物介导的RNAi技术，分别干涉侵染前和侵染后线虫，分析对线虫生长发育影响，及不同AChE基因受抑制后，线虫对杀线剂敏感性差异，阐明了3个的基因功能，为利用RNAi技术防治根结线虫这一新的策略及线虫抗药性治理和开发高选择性杀线剂提供理论依据。项目资助发表核心论文4篇，待发表1篇。培养硕士生3名，其中1名已经取得硕士学位，2名在读。项目投入经费53万元，支出43.9836万元，各项支出基本与预算相符。剩余经费9.0164万元，剩余经费计划用于本项目。