Apis mellifera ion channels and tools to study agroecosystems contaminants

研究农业生态系统污染物的意大利蜜蜂离子通道和工具

• 批准号: RGPIN-2020-06359
• 负责人: CHAHINE, Mohamed
• 金额: $ 2.62万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=718298
• 关键词: Apis; mellifera; ion; channels; tools

The dramatic decline and disappearance of insect populations, and of many other species, around the world is now a scientific fact, with more than one million species on the endangered list. Insect populations have been harder hit, with a 75% to 98% decline in insect biomass in the last 25-40 years. Although there are many anthropogenic causes, chronic exposure to pesticides is central to the conflict between agricultural imperatives and environmental issues, which is front and centre in the political arena and most media. Despite the fact that the pesticides currently used in modern agriculture are relatively safe for humans, they can severely affect both target pests and beneficial insects. Pesticides include insecticides, herbicides, and fungicides. The most widely used insecticides are neurotoxic. The most active substances belong to 4 major families and target synaptic ion channels: GABA and nicotinic receptors (nAChR), which are targeted by fipronil and neonicotinoids, Nav channels, which are targeted by pyrethroids and other Nav blockers such as metaflumizone, and Choline esterase, which is targeted by organophosphates and methylcarbamates. Their ecotoxicological effects include a significant increase in the loss of honey bee colonies. We will perform in vitro analyses of a collection of commonly used pesticides on several ion channels expressed in the synapses of the honey bee (Apis mellifera) brain and will clone and characterize these channels in an expression system. We hypothesize that honey bee ion channels are sensitive to insecticides, which may explain their deleterious effect on these needed pollinators. Our research program hypothesis will be tested via 3 Aims: Aim #1: Identify, clone, and sequence GABA receptor subunit genes expressed at honeybee synapses and analyze their expression patterns in tissues from adult honey bees and larvae. Characterize, after expression in Xenopus oocytes, the biophysical and pharmacological properties of these pore-forming subunits as well as the effects of a panel of pesticides currently used for agricultural or domestic purposes. Aim #2: Identify, clone, and sequence nAChR receptor subunit genes expressed at honeybee synapses, characterize their expression in Xenopus oocytes, and study their biophysical and pharmacological properties well as the effects of pesticides currently used for agricultural or domestic purposes, including neonic pesticides. Aim #3: Produce a molecular model of each channel type onto which effective molecules can be docked to better understand the molecular mechanisms of ion channel regulation and identify possible species specificities through structural/sequence variations. Impact: This project will in fine provide an invaluable tool for providing an in-depth understanding of the toxicity of the main phytopharmaceutical products and will constitute the first comprehensive molecular and functional characterization of a complete synaptic channelome.

昆虫种群以及世界上许多其他物种的急剧下降和消失现在是一个科学事实，濒临灭绝的列表中有超过一百万种。昆虫种群受到了困难，在过去的25 - 40年中，昆虫生物量下降了75％至98％。尽管有许多人为原因，但长期暴露于农药是农业要求与环境问题之间的冲突至关重要的，这是政治舞台和大多数媒体的前沿和中心。尽管现代农业目前使用的农药对人类相对安全，但它们可能会严重影响目标害虫和有益的昆虫。 农药包括杀虫剂，除草剂和杀菌剂。使用最广泛的杀虫剂是神经毒性。最活跃的物质属于4个主要家族和目标突触离子通道：GABA和烟碱受体（NACHR），它们是由fipronil和Neonicotinoids靶向的NAV通道，这些通道是拟甲藻类动物和其他NAV阻滞剂的靶向，例如Metaflumizone，Metaflumizone，Metaflumizone和Choline Esterase，Organsed tablesected tables tablesect tables tables table。它们的生态毒性作用包括蜜蜂菌落的丧失显着增加。我们将对在蜜蜂（Apis Mellifera）大脑突触中表达的几个离子通道上进行一系列常用农药的体外分析，并将克隆并在表达系统中表征这些通道。 我们假设蜜蜂离子通道对杀虫剂敏感，这可能解释了它们对这些所需传粉媒介的有害作用。我们的研究计划假设将通过3个目标进行检验： AIM＃1：识别以蜜蜂突触表达的GABA受体亚基基因，并分析其在成年蜜蜂和幼虫的组织中的表达模式。表征在爪蟾卵母细胞中表达后，这些孔形成亚基的生物物理和药理特性以及当前用于农业或家庭用途的一组农药的影响。 AIM＃2：识别以蜜蜂突触表达的NACHR受体亚基基因，表征其在Xenopus卵母细胞中的表达，并很好地研究其生物物理和药理特性，因为当前用于农业或家庭用途的农药的影响，包括神经农药。 AIM＃3：产生每种通道类型的分子模型，可以将有效分子停靠在其上，以更好地了解离子通道调节的分子机制，并通过结构/序列变化鉴定可能的物种特异性。 影响：该项目将提供一个宝贵的工具，以深入了解主要植物药物的毒性，并将构成完整突触通道组的首个综合分子和功能表征。