Developmental and Genetic Basis of Life History Variation along a Speciation Continuum

沿着物种连续体的生命史变异的发育和遗传基础

• 批准号: 262986-2013
• 负责人: Docker, Margaret
• 金额: $ 1.6万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=631735
• 关键词: Developmental; Genetic; Basis; Life; History

As scientists try to predict how populations will respond to rapid environmental change, it is becoming increasingly important to understand the genetic basis of adaptation and speciation. The role played by phenotypic plasticity (i.e., the ability of a single genotype to produce different phenotypes under different environmental conditions) is also important. Phenotypic plasticity can provide an immediate population-wide response to new or changing conditions, but how such environmentally-induced phenotypes lead to speciation (how they eventually become genetically fixed) is less clear. The proposed research will therefore test the relative importance of genetic and environmental factors (i.e., nature versus nurture) at different stages of evolution, using lampreys as a model system. Lampreys are ancient vertebrates which exhibit a rich diversity of life history types: they may feed parasitically on other fishes either at sea or in fresh water or, even more dramatically, may bypass the adult feeding phase altogether and reproduce at small sizes in their home streams. Some nonparasitic species are genetically distinct from their parasitic ancestor; in other cases, different migratory and feeding types show little or no genetic differentiation (i.e., represent the early stages of divergence). It appears that a single species may produce different life history types, but whether this is due to genetic polymorphism or phenotypic plasticity is unknown. The proposed research will be the first to test this, using complementary developmental (e.g., rearing offspring of different feeding types under common laboratory conditions) and genetic approaches. Understanding the basis of life cycle diversity has significant management implications (e.g., understanding what enabled the sea lamprey to become invasive in the Great Lakes). Being able to predict under what conditions invasion of fresh water systems could happen again is particularly important in the context of expected climate-driven changes to the relative productivity of marine and freshwater systems. This research will provide students with training in cutting-edge genomic technologies, producing personnel highly qualified for employment in research and development in academia and industry.

随着科学家试图预测种群将如何应对快速的环境变化，了解适应和物种形成的遗传基础变得越来越重要。表型可塑性（即，单一基因型在不同环境条件下产生不同表型的能力）也是重要的。表型可塑性可以提供对新的或变化的条件的即时群体反应，但这种环境诱导的表型如何导致物种形成（它们最终如何成为遗传固定）尚不清楚。因此，拟议的研究将测试遗传和环境因素的相对重要性（即，自然与养育）在不同的进化阶段，使用七鳃鳗作为模型系统。七鳃鳗是一种古老的脊椎动物，具有丰富的生活史类型多样性：它们可以寄生在海洋或淡水中的其他鱼类身上，或者更戏剧性的是，它们可以完全绕过成年摄食期，在它们的家乡河流中以小尺寸繁殖。一些非寄生物种在遗传上与它们的寄生祖先不同;在其他情况下，不同的迁徙和进食类型显示很少或没有遗传分化（即，代表分歧的早期阶段）。看来，一个单一的物种可能会产生不同的生活史类型，但这是否是由于遗传多态性或表型可塑性是未知的。拟议的研究将是第一个测试这一点，使用补充发展（例如，在普通实验室条件下饲养不同饲养类型的后代）和遗传方法。了解生命周期多样性的基础具有重要的管理意义（例如，了解是什么使海七鳃鳗成为入侵五大湖）。能够预测在何种条件下淡水系统可能再次受到入侵，在预期气候驱动的海洋和淡水系统相对生产力变化的背景下尤为重要。这项研究将为学生提供尖端基因组技术的培训，培养出在学术界和工业界从事研究和开发的高素质人才。