Molecular basis of egg-laying across mosquitoes

世界上有一半的人口面临感染蚊媒病毒疾病的风险，据估计，这一数字在未来50年将增加10亿。选择合适的产卵地点对蚊子等没有后续父母照料的动物的健康至关重要。我提议的探索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一些蚊子已经并继续在全球传播，而另一些蚊子仍然局限于特定的生态位，这对了解基本的蚊子生物学以及制定有针对性的控制策略具有重要意义。埃及伊蚊起源于撒哈拉以南非洲，但现在发现在全球广阔且迅速扩张的狭长地带，它们以两种主要方式剥削人类：i)专门利用人类的血液，它们用来产卵；ii)在与人类居住相关的小淡水水体中产卵，如饮用水容器、轮胎或废弃的建筑物。天哪。埃及伊蚊幼虫在高于~10%海水的咸水中死亡，成年雌性避免在这些盐度下产卵。相比之下，伊蚊在城市环境中不存在，在北美西部和亚洲海岸的咸水和微咸水岩池中繁殖，幼虫能够耐受从淡水到300%海水的盐度。关于Ae是如何形成的，人们知之甚少。袋鼠选择产卵地点，尽管生活史特征不同，并从热带传播到亚北极，但它们的活动范围仍然局限于海岸。我们建议进一步探索在Ae上对比产卵策略、幼虫生理和栖息地利用灵活性的基础。Aegypti和Ae.目标1：确定指导蚊子产卵偏好的行为策略。Aegypti和Ae.TOGOI使用定量行为分析和人工选择目标2：利用从头开始的基因组组装和转录组学为海水和淡水繁殖的蚊子建立比较基因组学方法目标3：利用CRISPR/Cas9引入新的等位基因并阐明电路解剖和功能，以确定导致产卵偏好改变的原因分子机制和神经回路。本研究项目将通过将比较方法与靶向遗传操作相结合，阐明蚊子栖息地开发的遗传和行为适应。了解昆虫神经系统如何适应并允许开发新的生态位，对于预测和预防农业有害生物种类和人类和动物病原体媒介在快速变化的世界中范围的扩大至关重要。

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.