NSFGEO-NERC: Mechanisms of Adaptation to Terrestrial Antarctica through Comparative Physiology and Genomics of Antarctic and sub-Antarctic Insects

南极洲寒冷干燥的陆地环境不适合昆虫生存，只有三种蠓栖息在南极洲。其中，Belgica antarctica是唯一只在南极洲发现的物种，自3000万年前南极洲从南美洲分裂出来以来，它一直是南极洲的居民。因此，这个物种是一个很好的系统，可以模拟南极洲的生物历史，包括反复的冰川事件和气候变化。这种昆虫也是极端适应的典型例子，以前的许多工作都集中在确定遗传和生理机制上，这些机制使这种物种能够在其他昆虫无法生存的地方生存。然而，由于缺乏密切相关的南极和亚南极物种的信息，很难确定在南极洲生存所需的独特进化适应。该项目将比较从亚南极到南极栖息地的环境梯度中四种蠓的适应性、基因组序列和种群特征。除了B. antarctica外，这些物种还包括两个严格意义上属于亚南极的物种，以及第三个原产于亚南极但已入侵南极洲部分地区的物种。由来自美国、英国、智利和法国的科学家组成的研究人员将从昆虫的地理分布范围内取样，测量它们耐受环境压力源（即寒冷和干燥）的能力，量化分子对压力的反应，并比较基因组的组成和遗传多样性的模式。这项研究将有助于更好地了解对极端气候的适应，了解地球上的生物多样性，以及了解和预测伴随环境变化的变化。该项目将培训两名研究生和两名博士后研究人员，一名K-12教育工作者将成为实地小组成员，协助实地工作，并促进与美国学校的联系。该项目包括与几个STEM教育组织的合作活动，向K-12和中学生提供教育内容。该项目由美国国家科学基金会地球科学理事会（NSF/GEO）和英国国家环境研究委员会（NERC）通过NSF/GEO-NERC牵头机构协议共同资助。该协议允许美国/英国提交一份联合提案，并由其调查员拥有最大比例预算的机构进行同行评审。每个机构为预算中与本国有关的比例和调查人员提供经费。英国参与该项目包括派遣科学家作为实地小组的一员，支持南极偏远地点的实地和采样后勤，以及基因组测序、注释和分析。这个项目的重点是关键的生理适应和分子过程，允许选择少数昆虫物种在南极洲生存。焦点物种都是无翅的，传播能力有限，这表明这些物种在局部适应多变的环境条件方面也有很大的潜力。核心假设是，相似的分子机制驱动了种群水平对当地环境条件的适应，以及生活在不同环境中的物种的宏观进化变化。该项目的具体目标是：1)通过比较生理学和转录组学来表征保守物种和物种特有的极端环境适应性；2)比较这些物种的基因组序列，以确定极端适应的遗传特征；3)研究每个物种的多样化和局部适应模式。范围使用人口基因组学。该项目建立了来自美国、英国、智利和法国的研究人员的国际合作，他们在生物学、基因组学和南极节肢动物保护方面有着共同的兴趣和互补的专业知识。该项目的更广泛影响包括培训学生，并与生活艺术和科学中心合作，为K-12学生设计和实施教育内容。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The cold, dry terrestrial environments of Antarctica are inhospitable for insects, and only three midge species make Antarctica home. Of these, Belgica antarctica is the only species found exclusively in Antarctica, and it has been a resident of Antarctica since the continent split from South America ~30 million years ago. Thus, this species is an excellent system to model the biological history of Antarctica throughout its repeated glaciation events and shifts in climate. This insect is also a classic example of extreme adaptation, and much previous work has focused on identifying the genetic and physiological mechanisms that allow this species to survive where no other insect is capable. However, it has been difficult to pinpoint the unique evolutionary adaptations that are required to survive in Antarctica due to a lack of information from closely related Antarctic and sub-Antarctic species. This project will compare adaptations, genome sequences, and population characteristics of four midge species that span an environmental gradient from sub-Antarctic to Antarctic habitats. In addition to B. antarctica, these species include two species that are strictly sub-Antarctic and a third that is native to the sub-Antarctic but has invaded parts of Antarctica. The researchers, comprised of scientists from the US, UK, Chile, and France, will sample insects from across their geographic range and measure their ability to tolerate environmental stressors (i.e., cold and desiccation), quantify molecular responses to stress, and compare the makeup of the genome and patterns of genetic diversity. This research will contribute to a greater understanding of adaptation to extremes, to an understanding of biodiversity on the planet and to understanding and predicting changes accompanying environmental change. The project will train two graduate students and two postdoctoral researchers, and a K-12 educator will be a member of the field team and will assist with fieldwork and facilitate outreach with schools in the US. The project includes partnership activities with several STEM education organizations to deliver educational content to K-12 and secondary students. This is a project that is jointly funded by the National Science Foundation's Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Each Agency funds the proportion of the budget and the investigators associated with its own country. UK participation in this project includes deploying scientists as part of the field team, supporting field and sampling logistics at remote Antarctic sites, and genome sequencing, annotation, and analyses. This project focuses on the key physiological adaptations and molecular processes that allow a select few insect species to survive in Antarctica. The focal species are all wingless with limited dispersal capacity, suggesting there is also significant potential to locally adapt to variable environmental conditions across the range of these species. The central hypothesis is that similar molecular mechanisms drive both population-level adaptation to local environmental conditions and macroevolutionary changes across species living in different environments. The specific aims of the project are to 1) Characterize conserved and species-specific adaptations to extreme environments through comparative physiology and transcriptomics, 2) Compare the genome sequences of these species to identify genetic signatures of extreme adaption, and 3) Investigate patterns of diversification and local adaptation across each species? range using population genomics. The project establishes an international collaboration of researchers from the US, UK, Chile, and France with shared interests and complementary expertise in the biology, genomics, and conservation of Antarctic arthropods. The Broader Impacts of the project include training students and partnering with the Living Arts and Science Center to design and implement educational content for K-12 students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.