Molecular Evolution of Vertebrate Visual Systems

脊椎动物视觉系统的分子进化

• 批准号: RGPIN-2021-03646
• 负责人: Schott, Ryan
• 金额: $ 2.04万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742659
• 关键词: Molecular; Evolution; Vertebrate; Visual; Systems

Determining how organisms adapt to their environments is a fundamental goal of evolutionary biology. Sensory systems, such as vision, are an ideal model to study this topic, as they provide a direct interface between an organism and its environment. The long-term objective of my research program is to better understand the evolution of vertebrate visual systems and how they develop and adapt in response to different sensory environments. My research takes an innovative and integrative approach that combines comparative genomics and evolutionary computational analyses with targeted experiments to provide a comprehensive view of visual system evolution and function at multiple organizational scales. Amphibians (frogs, salamanders, and caecilians) provide an excellent system within which to study the evolution and adaptation of visual systems. They are a diverse group (~8200 species) that has convergently evolved many different life histories and behaviors, including subterranean lifestyles, providing the opportunity to study repeated adaptation in the visual system. Amphibians also encapsulate an important evolutionary transition in vertebrate evolution from aquatic to terrestrial environments, which imposed drastically different spectral and optical constraints on the visual system. This transition between aquatic and terrestrial environments also occurs during the life cycle of many amphibians with the transition from aquatic larvae (tadpoles) to terrestrial juveniles, further providing an opportunity to explore the intersection of evolution and development in adaptation of the visual system. Amphibians also have a novel type of light-sensitive photoreceptor that may enable nocturnal colour vision in dim light when most other animals are colour-blind. Despite these unique aspects of amphibians that make them a particularly compelling model for visual biology, the study of amphibian visual systems has fallen well behind other vertebrate groups. We will conduct the first integrative analysis of visual gene evolution across amphibians providing deep insight into the constraints and opportunities of visual systems to evolving novel solutions to new life history modes and behaviors. Complementary studies of frog and salamander visual gene expression across ontogeny will reveal the role of developmental changes in visual adaptation. We will also investigate visual adaptation in amphibians and reptiles that convergently evolved subterranean lifestyles using comparative genomic approaches. Finally, we will study the novel amphibian photoreceptor using single cell transcriptome sequencing and cellular imaging to uncover its evolutionary and developmental history. This will further lay the foundation for future studies of photoreceptor evolution and development in vertebrates. This research program will create a rich environment for a diverse group of trainees to make major contributions using cutting-edge techniques in evolutionary genomics.

确定生物如何适应环境是进化生物学的基本目标。视觉等感觉系统是研究这一主题的理想模型，因为它们提供了生物体与环境之间的直接界面。我的研究计划的长期目标是更好地了解脊椎动物视觉系统的进化，以及它们如何发展和适应不同的感官环境。我的研究采取了一种创新和综合的方法，将比较基因组学和进化计算分析与有针对性的实验相结合，以提供视觉系统进化和功能在多个组织规模的全面视图。两栖动物（青蛙、蝾螈和螈）提供了一个很好的系统来研究视觉系统的进化和适应。它们是一个多样化的群体（约8200种），已经趋同地进化出许多不同的生活史和行为，包括地下生活方式，为研究视觉系统的重复适应提供了机会。两栖类也包含了脊椎动物从水生环境到陆地环境的重要进化过渡，这对视觉系统施加了截然不同的光谱和光学限制。水生和陆生环境之间的这种过渡也发生在许多两栖动物的生命周期中，从水生幼虫（蝌蚪）过渡到陆生少年，进一步提供了探索视觉系统适应进化和发展的交叉点的机会。两栖动物也有一种新型的光敏感光器，当大多数其他动物是色盲时，它可以在昏暗的光线下实现夜间色觉。尽管两栖动物的这些独特方面使它们成为视觉生物学特别引人注目的模型，但两栖动物视觉系统的研究远远落后于其他脊椎动物群体。我们将对两栖动物的视觉基因进化进行第一次综合分析，深入了解视觉系统的限制和机会，以发展新的生活史模式和行为的新解决方案。青蛙和蝾螈的视觉基因表达在个体发育的补充研究将揭示视觉适应的发展变化的作用。我们还将使用比较基因组方法研究两栖动物和爬行动物的视觉适应，这些动物逐渐进化出地下生活方式。最后，我们将使用单细胞转录组测序和细胞成像来研究新的两栖动物光感受器，以揭示其进化和发展历史。这将为进一步研究脊椎动物感光细胞的进化和发育奠定基础。该研究计划将为多样化的学员群体创造一个丰富的环境，利用进化基因组学的尖端技术做出重大贡献。