Molecular basis of egg-laying across mosquitoes

蚊子产卵的分子基础

• 批准号: RGPIN-2020-05423
• 负责人: Matthews, Benjamin
• 金额: $ 3.42万
• 依托单位: University of British Columbia
• 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=717636
• 关键词: Molecular; basis; egg; laying; across

Half the world's population is at risk of contracting mosquito-borne viral disease and it is estimated that this number will grow by 1 billion over the next 50 years. Selecting an appropriate oviposition (egg-laying) site is critical to fitness in animals like mosquitoes that perform no subsequent parental care. The broad objective of my proposed Discovery Grant is to understand, at the molecular genetic and neural circuit level, how different species of mosquito decide where to oviposit. This work will help determine why some mosquitoes have spread, and continue to spread, across the globe while others remain restricted to specific ecological niches with important implications for understanding basic mosquito biology as well as developing targeted control strategies. Aedes aegypti originated in sub-Saharan Africa but are now found across a broad and rapidly expanding swath of the globe where they exploit human beings in two primary ways: i) specializing on humans for blood, which they use to develop eggs and ii) laying eggs in small bodies of fresh water associated with human settlement, such as drinking water containers, tires, or abandoned structures. Ae. aegypti larvae die in brackish water above ~10% seawater and adult females avoid ovipositing in these salinities. By contrast, Aedes togoi are not found in urban environments and breed in saline and brackish rockpools along the coast of western North America and Asia, with larvae able to tolerate salinities ranging from freshwater to 300% seawater. Little is known about how Ae. togoi select oviposition sites and, despite variation in life history traits and spread from the tropics to the subarctic, their range remains restricted to the coast. We propose to explore the basis of contrasting oviposition strategies, larval physiology, and habitat utilization flexibility across Ae. aegypti and Ae. togoi mosquitoes, with the following specific objectives: Objective 1: Determine the behavioural strategies guiding oviposition preference in Ae. aegypti and Ae. togoi using quantitative behavioural analysis and artificial selection Objective 2: Develop a comparative genomics approach for salt- and fresh-water breeding mosquitoes using de novo genome assembly and transcriptomics Objective 3: Identify causal molecular mechanisms and neural circuits underlying shifting oviposition preference using CRISPR/Cas9 to introduce novel alleles and elucidate circuit anatomy and function This research program will shed light on genetic and behavioural adaptations underlying habitat exploitation in mosquitoes by coupling a comparative approach with targeted genetic manipulation. Understanding how insects' nervous systems adapt and allow for exploitation of novel ecological niches is critical to predicting and pre-empting range increase of agricultural pest species and vectors of human and animal pathogens in a rapidly changing world.

世界上有一半的人口面临着感染蚊子传播的病毒性疾病的风险，据估计，这一数字在未来50年将增加10亿。选择一个适当的产卵（产卵）地点是至关重要的健康动物，如蚊子，不执行后续的父母照顾。我提出的“发现基金”的广泛目标是在分子遗传和神经回路水平上了解不同种类的蚊子如何决定在哪里产卵。这项工作将有助于确定为什么有些蚊子已经传播，并继续传播，在地球仪，而其他人仍然限于特定的生态位与重要的影响，了解基本的蚊子生物学以及制定有针对性的控制策略。 埃及伊蚊起源于撒哈拉以南的非洲，但现在在地球仪的广泛且迅速扩大的地带发现，它们以两种主要方式剥削人类：i）专门针对人类的血液，它们用来发育卵，ii）在与人类定居点有关的小型淡水中产卵，如饮用水容器，轮胎或废弃结构。AE.埃及伊蚊幼虫在高于~10%海水的微咸水中死亡，成年雌性避免在这些盐度中产卵。相比之下，在城市环境中没有发现东埃及伊蚊，它们在北美西部和亚洲沿着的盐水和半咸水岩池中繁殖，其幼虫能够耐受从淡水到300%海水的盐度。很少有人知道如何Ae。托戈伊选择产卵地点，尽管生活史特征各不相同，并从热带向亚北极扩散，但其活动范围仍限于沿海地区。我们建议探索的基础上，比较产卵策略，幼虫生理，和栖息地利用的灵活性跨越Ae。埃及伊蚊和埃及伊蚊。多哥蚊子，具体目标如下： 目的1：研究金纹伊蚊产卵选择的行为策略。埃及伊蚊和埃及伊蚊。多哥使用定量行为分析和人工选择 目标2：利用从头基因组组装和转录组学，发展一种比较基因组学方法，用于盐和淡水繁殖的蚊子 目标3：使用CRISPR/Cas9识别转变产卵偏好背后的因果分子机制和神经回路，以引入新的等位基因并阐明回路解剖学和功能 这项研究计划将通过将比较方法与有针对性的遗传操作相结合，揭示蚊子栖息地开发的遗传和行为适应。了解昆虫的神经系统如何适应并允许利用新的生态位，对于预测和预防农业害虫物种以及人类和动物病原体载体在快速变化的世界中的范围增加至关重要。