The role of sex, climate change, and land use on the spread of aphid pesticide-resistance in the UK: a PhD project using transcriptomic and GIS-based

该项目将尖端的环境建模技术与生理和基因组分析相结合，以了解最近在英国向较冷气候地区传播的抗杀虫剂谷物蚜虫。该学生的工作将在严格理解环境驱动因素和生理机制的基础上，为控制抗性克隆的传播提供环境管理选择。这项工作还将为进化过程提供基本的见解。作物害虫中杀虫剂抗性的进化和传播既是对粮食安全的重大挑战，也是了解环境变化条件下进化过程的重大机遇。在这方面，蚜虫提供了一个理想的研究系统，因为它们对气候和杀虫剂的适应速度很快，这是由它们具有有性和无性阶段的复杂生命周期驱动的（Fenton et al. 2010）。直到最近，谷物蚜虫（Sitobion avenae）的抗杀虫剂无性系仅限于英国南部地区。然而，在过去的几年里，英国北部温暖的冬天使得无性系蚜虫常年存在，人们怀疑，不那么严酷的冬天加上不断变化的杀虫剂使用模式，可能会促进苏格兰抗杀虫剂无性系的越冬。在这个项目中，我们将解决以下问题：1)为什么抗性仅限于S. avenae的无性克隆？2)抗虫性和耐寒性之间是否存在生理上的权衡？3)有哪些环境因素有利于增加成功,insecticide-resistant克隆在苏格兰,和我们如何使用这些信息来限制他们的传播吗?为了解决这些问题，学生将承担：1)抗性机制和权衡的生理和转录基础。该学生将田间收集的抗性和易感无性系，以及易感性系，暴露在杀虫剂暴露和温度的不同组合中，以确定生理后果。对这些处理类别的个体进行转录组学分析可以揭示在抗寒性和杀虫剂抗性之间观察到的生理权衡的遗传基础。2)利用GIS和空间建模技术了解克隆频率的环境驱动因素。为此，学生将依靠SASA （CASE合作伙伴）对过去几年苏格兰抗性蚜虫频率的大型数据集的访问。数据是通过在英国不同地点的四个吸力陷阱捕获的蚜虫进行基因分型收集的（http://www.rothamsted.ac.uk/insect-survey/about）。利用微卫星DNA，取样的蚜虫可归因于先前描述的耐药和易感菌株（Foster et al. 2015）。利用基于gis的联合物种分布模型（JDSM）的新方法，学生将蚜虫抗性与气候和天气模式、土地利用、杀虫剂使用以及收集的S. avenae和其他蚜虫物种的总丰度联系起来。该学生将在阿伯丁大学充满活力的生物与环境科学研究所工作，该研究所是世界领先的环境与农业科学研究所。在那里，学生将加入莱斯利·兰开斯特博士的研究小组（www.lancasterlab.weebly.com）。该小组正在进行的项目包括基因组技术、联合物种分布模型和实验进化，以了解气候变化下的群落相互作用、害虫动态和生态位进化。该项目的联合主管是邓迪詹姆斯·赫顿研究所（JHI）的盖纳·马洛赫博士。Malloch博士是蚜虫生物学方面的专家，JHI是世界领先的粮食安全研究机构。该学生还将定期与爱丁堡SASA的昆虫学团队联络，收集数据。

This project combines cutting-edge environmental modelling techniques with physiological and genomic analyses to understand the recent spread of insecticide-resistant grain aphids towards cooler climates in the UK. The student's work will inform environmental management options for controlling the spread of resistant clones, based on rigorous understanding of environmental drivers and physiological mechanisms. The work will also provide fundamental insight into the evolutionary process.The evolution and spread of insecticide resistance in crop pest insects is both a major challenge for food security, and a major opportunity to understand the evolutionary process under conditions of environmental change. Aphids provide an ideal study system in this regard, because they exhibit rapid adaptation to both climate and pesticides, driven by their complex life cycles with both sexual and asexual phases (Fenton et al. 2010). Until recently, insecticide-resistant clonal lines of the grain aphid (Sitobion avenae) were restricted to the southern parts of the UK. In the last few years, however, warmer winters in the north of the UK have allowed clonal aphid lines to persist year around, and it is suspected that less severe winters combined with changing insecticide use patterns may facilitate overwintering of insecticide resistant clones in Scotland. In this project we will address the following questions: 1) Why is insecticide-resistance limited to asexual clones of S. avenae?2) Is there a physiological trade-off between insecticide resistance and cold-hardiness?3) What are the environmental factors favouring the increase in successful, insecticide-resistant clones in Scotland, and how can we use this information to limit their spread? To address these questions, the student will undertake: 1) Physiological and transcriptomic basis of resistance mechanisms and trade-offs. The student will expose field-collected resistant and susceptible clonal lines, as well as susceptible sexual lineages, to different combinations of insecticide exposure and temperature, to determine physiological consequences. Transcriptomic analysis of individuals from these treatment categories can reveal genetic basis for observed physiological trade-offs between cold resistance and insecticide resistance. 2) GIS and spatial modelling to understand the environmental drivers of clonal frequencies. For this, the student will rely on SASA's (the CASE partner) access to a large dataset on the frequency of resistant aphids in Scotland over the past several years. Data have been gathered by genotyping aphids captured in four suction traps located at various locations across the UK (http://www.rothamsted.ac.uk/insect-survey/about). Using microsatellite DNA, sampled aphids can be attributed to previously described resistant and susceptible strains (Foster et al. 2015). Using the novel GIS-based approach of joint species distribution modelling (JDSM), the student will correlate aphid resistance with climate and weather patterns, land use, insecticide use, and the total abundances of S. avenae and other aphid species in the collections. The student will be based at the University of Aberdeen, in the dynamic Institute of Biological & Environmental Sciences, a world-leading institute for environmental and agricultural science. There the student will join the research group of Dr Lesley Lancaster (www.lancasterlab.weebly.com). Ongoing projects in the group involve genomic techniques, joint species distribution modelling, and experimental evolution to understand community interactions, pest dynamics, and niche evolution under climate change. The co-supervisor on the project is Dr Gaynor Malloch of the James Hutton Institute (JHI) in Dundee. Dr Malloch an expert in aphid biology, and JHI is a world-leading research institute for food security. The student will also liaise regularly with the Entomology team at SASA in Edinburgh to gather data.