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其他物种来获取食物或吸引配偶，这些物种之间的有益伙伴关系被称为互利共生，尽管互利共生对于生存和繁殖是必要的，但它们是有代价的：形成互利共生通常会使个体毫无防备。这项研究将调查寄生虫何时以及如何影响互利共生的功能和进化，研究人员将在依赖共生细菌提供关键营养的豆类植物（苜蓿、豌豆和豆类）中测试这些问题。在使用苜蓿及其近亲的一系列实验中，研究人员将确定寄生虫如何影响用于形成互利共生的植物基因的进化，并测试某些互利伙伴关系（即植物-细菌对）是否比寄生虫对它们的影响更小。这项研究很重要，因为几乎所有农作物都依赖真菌或细菌获取营养，因此了解寄生虫何时以及如何危害此类互利共生对于保护这些具有经济和生态意义的伙伴关系至关重要。培训初级科学家和两个新项目，向生物学本科生教授数据分析（一项基本科学技能）。这项研究的总体目标是检验一个中心假设，即遗传多效性（当同一基因影响多个性状时）是一种广泛且普遍的现象。该项目将在苜蓿属豆科植物和固氮细菌之间的互利共生模型中检验这一假设。许多涉及细菌互利共生的植物基因与对寄生根结的抵抗力有关。该项目具有三个目标：（1）通过比较多效性基因选择与互利共生和寄生的群体基因组特征，测试连接互利共生和寄生的多效性是否限制了两种相互作用的基因进化。 (2) 通过测试多效性与寄生性的权衡是否持续存在于多种共生细菌菌株中，评估多效性是否具有环境依赖性，整合种群(3) 通过比较六个苜蓿物种的细菌互利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保守。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。