NSF Postdoctoral Fellowship in Biology FY 2020

2020 财年 NSF 生物学博士后奖学金

• 批准号: 2010658
• 负责人: Micah Freedman
• 金额: $ 13.8万
• 依托单位: Freedman Micah G
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2010658&HistoricalAwards=false
• 关键词: NSF; Postdoctoral; Fellowship; Biology; FY

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2020, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. Insects that eat plants comprise the vast majority of terrestrial animal species, and most specialize on a small number of plant species. Understanding host specialization in insects is thus important for understanding the diversity of life on Earth. One hypothesis for the prevalence of host specialization is that it allows insects to incorporate toxic host plant chemicals into their own tissues. This process is known as sequestration and helps to confer chemically-mediated protection against predators and pathogens. Sequestration in insects is best-known from the monarch butterfly (Danaus plexippus), whose larvae feed on milkweed plants containing toxic chemicals (cardenolides) that make them distasteful to predators. Although monarch sequestration has been studied, the genes involved in cardenolide uptake and transport remain unknown, and it is also unclear whether the monarch’s ability to sequester cardenolides is a cause or a consequence of specializing on milkweed host plants. This research will answer these basic questions about monarchs while involving undergraduates from underrepresented groups in this investigation; educational workshops will encourage the citizen science practices. The approaches below will link variation in genes (ATPα1 binding domain, transporters) to variation in a phenotype (sequestration ability) that affects the way that monarchs interact with their environment. In the first approach, the Fellow will leverage natural variation in cardenolide content of two milkweed species and natural variation in the ability of monarch populations to sequester cardenolides. Using experimental rearing and gene expression analysis, the Fellow will determine the genes involved in the process of cardenolide transport and storage, and how these genes differ in expression across hosts, monarch populations, and developmental stages. In the second approach, the Fellow will use “evolution-in-reverse” to understand which evolved first: the monarch’s target site insensitivity to cardenolides or the ability to sequester cardenolides. The Fellow will use gene-editing techniques (CRISPR-Cas9) to introduce a series of stepwise mutations into the cardenolide target site (the Na+/K+-ATPase) to determine whether sequestration is still possible on a cardenolide-sensitive background. The Fellow will gain valuable training in molecular biology, chemical ecology, and bioinformatics as well as in outreach by expanding the Monarch Larvae Monitoring Program to Puerto Rico.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.

这项行动资助了2020财年的NSF生物学博士后研究奖学金，综合研究调查了基因组，环境和表型之间的生命相互作用的规则。该研究金支持研究员的研究和培训，以创新的方式为生活规则领域做出贡献。以植物为食的昆虫包括绝大多数陆生动物物种，并且大多数专门针对少数植物物种。因此，了解昆虫的宿主专业化对于了解地球上生命的多样性非常重要。关于寄主专化现象的普遍性的一个假设是，它允许昆虫将有毒的寄主植物化学物质结合到它们自己的组织中。这一过程被称为隔离，有助于提供化学介导的保护，防止捕食者和病原体。昆虫中的隔离作用最为人所知的是帝王蝶（Danaus plexippus），其幼虫以含有有毒化学物质（Cardenolides）的马利筋植物为食，这些化学物质使它们对捕食者感到厌恶。虽然已经研究了帝王蝶的隔离作用，但参与Cardenolide摄取和运输的基因仍然未知，并且也不清楚帝王蝶隔离Cardenolides的能力是专门针对乳草宿主植物的原因还是结果。这项研究将回答这些关于君主的基本问题，同时涉及来自代表性不足群体的本科生在这项调查中，教育研讨会将鼓励公民科学的做法。 下面的方法将把基因（ATPα1结合结构域、转运蛋白）的变异与影响帝王蝶与环境相互作用方式的表型（螯合能力）的变异联系起来。在第一种方法中，研究员将利用两种乳草属物种的Cardenolide含量的自然变化和帝王蝶种群螯合Cardenolides能力的自然变化。通过实验饲养和基因表达分析，研究员将确定参与Cardenoprotein运输和储存过程的基因，以及这些基因在宿主，君主种群和发育阶段的表达差异。在第二种方法中，研究员将使用“逆向进化”来了解哪一个首先进化：帝王蝶的目标部位对Cardenolides不敏感或螯合Cardenolides的能力。该研究员将使用基因编辑技术（CRISPR-Cas9）将一系列逐步突变引入到Cardenolide靶位点（Na+/K+-ATPase）中，以确定在Cardenolide敏感的背景下是否仍有可能进行螯合。该研究员将获得分子生物学，化学生态学和生物信息学方面的宝贵培训，以及通过将Monarch Laravirus Monitoring Program扩展到波多黎各进行推广。该奖项反映了NSF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。