Getting to the Root of Flexible Stems: The Primary Cilia as a Proximate Mechanism of Plasticity and Evolution of the Cichlid Jaw

探究柔性茎的根源：初级纤毛作为慈鲷下颌可塑性和进化的近端机制

• 批准号: 1558003
• 负责人: Craig Albertson
• 金额: $ 74.7万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1558003&HistoricalAwards=false
• 关键词: Getting; Root; Flexible; Stems; Primary

How biodiversity arises and is maintained over time remains an important area of study. Adaptive radiations represent extreme instances of morphological evolution in response to discrete ecological shifts, and are thought to have made significant contributions to biodiversityon this planet. This research seeks to identify and characterize the genetic and cellular mechanisms that promote adaptive radiations, and thus to provide novel insights into the origins of biodiversity. This highly interdisciplinary project provides a rich intellectual landscape to train students in various methods and theories. It also offers an explicit framework to develop pedagogical tools for conveying evolutionary principals to the public. This will be part of on-going efforts to develop a series of animated and interactive evolutionary "origin stories" that detail the genetic mechanisms that underlie the development and evolution of notable traits, including turtle shells, bat wings, and limb loss in whales. Here the team proposes a new chapter-- Making faces: How the fish changes its skull.A focal point of this project is phenotypic plasticity, which refers to the ability of an organism to change its appearance in response to a change in the environment. The ability of an individual to change its phenotype in different environments may increase its fitness in changing and/or fluctuating environments, which suggests that plasticity may be adaptive and therefore subject to selection itself. It is predicted that species that live in fluctuating environments will maintain a high degree of plasticity. Conversely, species that live in more stable environments are predicted to loose the ability to mount a plastic response, and exhibit fixed phenotypes. Unfortunately, a strict genetic basis for phenotypic plasticity has remained elusive, and thus the evolutionary potential for this trait remains largely unknown. The goal of this research is to characterize the molecular basis for phenotypic plasticity of the teleost jaw. An emphasis on the jaws has direct ecological consequences, as different jaw shapes will determine where a fish lives and what it feeds on. Mutant and transgenic zebrafish will be used to assess the degree to which key molecules involved in bone formation, including those that underlie the primary cilia and Hedgehog signaling, are necessary to promote phenotypic plasticity in the skull and jaws. The molecular mechanisms that underlie plasticity will then be compared to patterns of genetic evolution in a textbook adaptive radiation, East African cichlid fishes, which exhibit extensive diversity in the shape of their jaws. It is predicted that the genes that underlie plasticity of the feeding apparatus, also underlie evolution of the jaws. This is because genetic variation that leads to plasticity is predicted to become "fixed" as populations adapt to new environments over time. In all, research under this award will facilitate a better understand of how the genome and environment interact to promote biodiversity.

生物多样性是如何产生并随着时间的推移而保持的，这仍然是一个重要的研究领域。 适应性辐射代表了形态进化的极端例子，以响应离散的生态变化，并被认为对地球上的生物多样性做出了重大贡献。这项研究旨在确定和表征促进适应性辐射的遗传和细胞机制，从而为生物多样性的起源提供新的见解。 这个高度跨学科的项目提供了丰富的知识景观，以培养学生在各种方法和理论。它还提供了一个明确的框架，以开发教学工具，向公众传达进化的原则。这将是正在进行的努力的一部分，以开发一系列动画和互动的进化“起源故事”，详细说明了显着特征的发展和进化的遗传机制，包括海龟壳，蝙蝠翅膀和鲸鱼的肢体损失。在此，研究小组提出新的一章--做鬼脸：鱼如何改变头骨。这个项目的重点是表型可塑性，指的是生物体对环境变化的反应能力。个体在不同环境中改变其表型的能力可能会增加其在变化和/或波动环境中的适应性，这表明可塑性可能是适应性的，因此受到选择本身的影响。 据预测，生活在波动环境中的物种将保持高度的可塑性。相反，生活在更稳定环境中的物种预计将失去安装塑性反应的能力，并表现出固定的表型。不幸的是，表型可塑性的严格遗传基础仍然难以捉摸，因此这种性状的进化潜力在很大程度上仍然未知。本研究的目的是描述硬骨鱼颌骨表型可塑性的分子基础。 对颌骨的重视有着直接的生态后果，因为不同的颌骨形状将决定鱼的生活地点和食物来源。突变和转基因斑马鱼将被用来评估参与骨骼形成的关键分子（包括初级纤毛和Hedgehog信号的基础分子）对促进头骨和颌骨表型可塑性的必要程度。可塑性的分子机制，然后将比较教科书适应性辐射，东非慈鲷鱼，其中表现出广泛的多样性，在他们的下巴形状的遗传进化模式。据预测，基因的基础可塑性的喂养机构，也是基础的进化的颌骨。这是因为随着时间的推移，随着种群适应新的环境，导致可塑性的遗传变异被预测为“固定”的。总之，该奖项下的研究将有助于更好地了解基因组和环境如何相互作用，以促进生物多样性。