Adaptive Evolution of Color Vision

色觉的适应性进化

• 批准号: 7342800
• 负责人: SHOZO YOKOYAMA
• 金额: $ 36.4万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7342800
• 关键词: Amino Acid Substitution; Amino Acids; Bayesian Method; Binding; Biological Models; Bioluminescence; Bos taurus; Cattle; Charge; Chemicals; Chemistry; Chimera organism; Color Visions; Computing Methodologies; DNA; Depth; Electrostatics; Engineering; Environment; Evolution; Fishes; Genes; Genetic; Globin; Goals; Habitats; Hybrids; Individual; Ions; Life; Light; Methods; Modeling; Molecular; Nature; Nucleotides; Object Attachment; Opsin; Organism; Pattern; Phototransduction; Phylogenetic Analysis; Pigments; Polyenes; Proteins; Range; Rate; Research; Research Personnel; Retinal; Retinal Pigments; Rhodopsin; Schiff Bases; Sea; Series; Site; Statistical Methods; Structure; Sunlight; Techniques; Testing; Time; Trees; Vertebrates; Vision; absorption; base; comparative; migration; novel strategies; programs; statistics

Organisms encounter a diverse array of habitats and adapt to these environments with an equally diverse array of structures and functions. The long-term goal of our studies is to elucidate mechanisms that drive these adaptive changes at the molecular and functional levels. We plan to accomplish this goal using vision as a model system. In the traditional view of phototfansduction, not only are amino acid (AA) sites .that are involved in the spectral tuning of visual pigments located only in or near the "retinal binding pocket" but also they modulate the wavelength of maximal absorption (Xmax) of visual pigments mostly in an additivefashion. It is now clear, however, that neither of these "assumptions" holds in nature. Hence, to identify all critical AA changes and understand their individual and synergistic effects on the Xmax-shift,some new approaches must be taken. Only when we establish the fundamental principle of the spectral tuning, the molecular mechanisms of adaptive evolution of visual pigments (and color vision) will be understood fully. Here we propose to clone all opsin genes of visual pigments of five deep-sea fishes lampfish (S. leucepsarus), loosejaw (A. scintillans), scabbardfish (L. fitchf), thornyhead (S. altivelis), and viperfish (C. macouni). We will then study both the molecular bases of spectral tuning and the mechanisms of adaptive evolution of visual pigments in a wide range of vertebrate species. Living at different depths, ranging from 200 to 4,000 m, the deep-sea fishes receive varying levels of sunlight at ~480 nm. In addition, the lampfish and viperfish emit bioluminescence at ~480 and the loosejaw at ~480 and ~700 nm. We plan to explore three features of visual pigments: 1) the molecular and chemical bases of the spectral tuning of visual pigments; 2) statisticaland experimental analysesof positively selected AA changes; and 3) co-evolution of paralogous pigments in each of the five deep-sea fish species. Using computational methods in theoretical chemistry, we plan to test four specific hypotheses of spectral tuning and identify the chemical principles by which absorption spectra of visual pigments are determined. To test whether the evolutionary patterns of different paralogouspigments are synchronized in each species according to the light distribution of the habitat, we shall comparethe evolutionary rates of nucleotide (or AA) substitution to those of the duplicated a and (3 globin genes in the same species, which will also be cloned and sequenced.

生物体会遇到各种各样的栖息地，并以同样多样化的方式适应这些环境 结构体和函数的数组。我们研究的长期目标是阐明驱动机制 这些在分子和功能水平上的适应性变化。我们计划利用愿景来实现这一目标 作为模型系统。在光诱导的传统观点中，不仅氨基酸（AA）位点是 参与仅位于“视网膜结合袋”内或附近的视色素的光谱调节，而且还涉及 它们主要以加法方式调节视觉色素的最大吸收波长（Xmax）。 然而现在很明显，这些“假设”在本质上都不成立。因此，要识别所有关键 AA 变化并了解它们对 Xmax-shift 的个体和协同效应，一些新方法 必须采取。只有当我们建立了光谱调谐的基本原理时，分子 视觉色素（和色觉）的适应性进化机制将得到充分理解。 在这里，我们建议克隆五种深海灯鱼（S. leucepsarus)、松颌鱼 (A. scintillans)、剑鱼 (L. fitchf)、刺头鱼 (S. altivelis) 和蝰鱼 (C. 马库尼）。然后我们将研究光谱调谐的分子基础和自适应机制 多种脊椎动物视觉色素的进化。生活在不同的深度，从 在 200 至 4,000 m 的深度，深海鱼类接受不同程度的约 480 nm 的阳光。此外，灯鱼 毒蛇鱼在 ~480 nm 处发出生物发光，松颌鱼在 ~480 和 ~700 nm 处发出生物发光。我们计划探索 视觉色素的三个特征：1）视觉光谱调节的分子和化学基础 颜料； 2）对阳性选择的AA变化进行统计和实验分析； 3）共同进化 五种深海鱼类中的每一种都具有旁系同源色素。在理论中使用计算方法 化学方面，我们计划测试光谱调谐的四种具体假设，并通过以下方式确定化学原理： 确定视色素的吸收光谱。检验进化模式是否 根据光分布，不同的旁系同源色素在每个物种中同步 栖息地，我们将比较核苷酸（或 AA）取代的进化速率与重复的进化速率 a和(同一物种的3个球蛋白基因，也将被克隆和测序。