The evolutionary significance of genetic pleiotropy in species interactions

遗传多效性在物种相互作用中的进化意义

• 批准号: 2118397
• 负责人: Corlett Wood
• 金额: $ 87.5万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2118397&HistoricalAwards=false
• 关键词: evolutionary; significance; genetic; pleiotropy; species

Nearly all plants and animals rely on other species for food or to attract mates. These beneficial partnerships between species are known as mutualisms. Although mutualisms are necessary for survival and reproduction, they come at a cost: often, forming a mutualism leaves an individual defenseless against parasites and other infections. This research will investigate when and how parasites affect the function and evolution of mutualisms. The researchers will test these questions in legume plants (alfalfa, peas, and beans) that rely on mutualistic bacteria for a key nutrient, nitrogen. In a series of experiments using alfalfa and its relatives, the researchers will determine how parasites affect the evolution of plant genes used to form mutualisms, and test whether some mutualistic partnerships (i.e., plant-bacteria pairs) are less affected by parasites than others. This research is important because nearly all crop plants rely on fungi or bacteria for nutrients, so understanding when and how parasites jeopardize mutualisms like these is essential to protect these economically and ecologically significant partnerships. The broader impacts of this project include training junior scientists and two new programs to teach data analysis—an essential scientific skill—to undergraduate biology students.The overarching goal of this research is to test the central hypothesis that genetic pleiotropy—when the same gene influences multiple traits—is a widespread and evolutionarily significant feature of species interactions. This project will test this hypothesis in the model mutualism between legumes in the genus Medicago and nitrogen-fixing bacteria. Many plant genes involved in the bacterial mutualism are implicated in resistance to parasitic root-knot nematodes, creating a genetic tradeoff between the two interactions. This project has three objectives: (1) Test whether pleiotropy linking mutualism and parasitism constrains the evolution of genes underlying both interactions by comparing population genomic signatures of selection at pleiotropic genes to mutualism- and parasitism-specific genes. (2) Evaluate whether pleiotropy is context dependent by testing whether pleiotropic tradeoffs with parasitism persist across multiple strains of mutualistic bacteria, integrating population genomics and quantitative genetics. (3) Determine whether pleiotropy is evolutionarily conserved by comparing the genetic tradeoff between the bacterial mutualism and resistance to parasitic nematodes across six Medicago species.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.

几乎所有的植物和动物都依赖于其他物种的食物或吸引配偶。物种之间的这种有益的伙伴关系被称为互惠。虽然互利共生是生存和繁殖所必需的，但它们是有代价的：通常，形成互利共生会使个体对寄生虫和其他感染毫无防御能力。这项研究将探讨寄生虫何时以及如何影响互惠的功能和进化。研究人员将在豆科植物（苜蓿，豌豆和豆类）中测试这些问题，这些植物依赖互利共生的细菌来获得关键的营养素，氮。在一系列使用苜蓿及其亲缘植物的实验中，研究人员将确定寄生虫如何影响用于形成互惠关系的植物基因的进化，并测试一些互惠关系（即，植物-细菌对）受寄生虫的影响比其他的要小。这项研究很重要，因为几乎所有的作物都依赖真菌或细菌提供营养，因此了解寄生虫何时以及如何危害这些互惠关系对于保护这些经济和生态上重要的伙伴关系至关重要。这个项目的更广泛的影响包括培训初级科学家和两个新的项目，教数据分析-一个基本的科学技能-本科生物学生。这项研究的首要目标是测试的核心假设，即遗传多效性-当同一个基因影响多个性状-是一个广泛的和进化的物种相互作用的重要特征。本计画将以苜蓿属豆科植物与固氮细菌间的互惠共生模式来验证此假说。许多植物基因参与了细菌的互利共生，涉及对寄生性根结线虫的抗性，从而在两种相互作用之间产生遗传权衡。本项目有三个目标：（1）通过比较多效基因与互惠和寄生特异性基因的选择的群体基因组特征，测试连接互惠和寄生的多效性是否限制了两者相互作用的基因的进化。(2)评估多效性是否是环境依赖性测试是否多效性权衡寄生持续跨多株互惠细菌，整合人口基因组学和数量遗传学。(3)通过比较六个苜蓿属物种之间的细菌共生和对寄生线虫的抗性之间的遗传权衡，确定多效性是否在进化上是保守的。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。