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Adaptive Evolution of Color Vision

色觉的适应性进化

基本信息

批准号：
8815313
负责人：
SHOZO YOKOYAMA
金额：
$ 37.98万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-02-01 至 2017-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8815313
关键词：
11 cis Retinal Amino Acid Sequence Amino Acids Animals Application procedure Attention Biological Models Biology Cells Characteristics Chemicals Color Visions Color vision defect Crustacea DNA Disease Engineering Environment Evolution Fishes Genetic Genetic Engineering Goals Habitats Health Hybrids Hydrogen Bonding Learning Life Life Style Light Measures Mechanics Methods Molecular Mutagenesis Mutate Nucleotides Organism Phototransduction Pigments Pike fish Problem Solving Procedures Process Proteins RH1 Research Retinal Dystrophy Retinal Pigments Retinitis Pigmentosa Rhodopsin Sampling Scientist Scombridae Spottings Squalus acanthias Structure Structure-Activity Relationship Surveys Testing Tuna UV sensitive Vertebrates Viola Vision absorption base fascinate interest novel strategies preconditioning quantum research study vision science

项目摘要

DESCRIPTION (provided by applicant): Animals have diversified and adapted to fill the numerous habitats and environments on this earth. 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. To identify critical amino acid (AA) changes that modify the wavelengths of maximal absorption (;maxs) of visual pigments, vision scientists analyze "contemporary" pigments. Experimental evolutionary biologists also manipulate "contemporary" pigments and infer the past. However, by ignoring the evolutionary processes of visual pigments, neither the molecular basis of spectral tuning in visual pigments nor the evolutionary mechanisms of visual pigments can be elucidated. Fortunately, the central unanswered questions in phototransduction and evolutionary biology can be solved simultaneously by genetically engineering and manipulating proper "ancestral pigments." Here, we propose to elucidate the molecular mechanisms that drive adaptive evolution of RH2, SWS1, and SWS2 pigments in vertebrates, which have ;maxs of ~450-530, ~355-440, and ~400-460 nm, respectively. We approach the problem not only by determining the molecular basis of spectral tuning in visual pigments but also by establishing the relationships between organisms with different sets of visual pigments and their ecological environments. For each pigment group, we plan to 1) infer the AA sequences of ~15 ancestral pigments and engineer them and determine their ;maxs, 2) infer AA changes that shift the ;max, 3) identify the critical AA changes by mutating ancestral pigments, and 4) establish the universal chemical principle of the spectral tuning in visual pigments by using the quantum mechanical/molecular mechanical (QM/MM) methods, which have been proven to be highly effective. We shall also test the possibility of adaptive evolution of these visual pigments by examining whether the directions of the ;max-shifts of visual pigments in various species match with the changes in the organisms' ecological environments. For this purpose, each of the three pigment groups with variable ;maxs in multiple species will be classified into distinct classes according to their environments and tested for the possibility of adaptive evolution. Since virtually all fish SWS1 pigments examined to date are UV-sensitive, we also plan to search for violet-sensitive SWS1 pigments in different fishes, by surveying fishes that live at depths of 0-200 m and prey on small fishes and do not require UV vision for hunting. Considering the strong AA interactions that occur in SWS1 pigments, we also plan to elucidate how various critical AA changes could have accumulated during its evolution and learn the chemical structural preconditions required for UV pigments to become violet-sensitive and vice versa.

描述（由申请人提供）：动物已经多样化并适应了地球上的众多栖息地和环境。我们研究的长期目标是阐明在分子和功能水平上驱动这些适应性变化的机制。我们计划使用视觉作为模型系统来实现这一目标。为了确定改变视色素最大吸收波长的关键氨基酸（AA）变化，视觉科学家分析了“当代”色素。实验进化生物学家也操纵“当代”色素并推断过去。然而，由于忽略了视色素的进化过程，无论是视色素光谱调谐的分子基础，还是视色素的进化机制都无法阐明。幸运的是，光传导和进化生物学中尚未解答的核心问题可以通过基因工程和操纵适当的“祖先色素”同时解决。“在这里，我们建议阐明驱动脊椎动物中RH 2，SWS 1和SWS 2色素适应性进化的分子机制，它们的最大值分别为~450-530，~355-440和~400-460 nm。我们不仅通过确定视色素光谱调谐的分子基础来解决这个问题，而且还通过建立具有不同视色素组的生物与其生态环境之间的关系来解决这个问题。对于每个色素组，我们计划1）推断~15个祖先色素的AA序列，并对其进行工程改造，并确定它们的最大值，2）推断AA变化，使其改变; max，3）通过突变祖先色素来识别关键的AA变化，以及4）通过使用量子力学/分子力学（QM/MM）方法来建立视色素中光谱调谐的普遍化学原理，已经被证明非常有效。我们还将通过观察不同物种视色素的最大位移方向是否与生物生态环境的变化相匹配来检验这些视色素适应性进化的可能性。为此，每个三个色素组变量;最大值在多个物种将被分为不同的类，根据其环境和适应性进化的可能性进行测试。由于几乎所有的鱼SWS 1色素检查到目前为止是紫外线敏感的，我们还计划寻找紫色敏感的SWS 1色素在不同的鱼类，通过调查生活在0-200米的深度和捕食小鱼，不需要紫外线视觉狩猎。考虑到SWS 1色素中发生的强烈AA相互作用，我们还计划阐明各种关键AA变化在其进化过程中如何积累，并了解UV色素变得对紫色敏感所需的化学结构先决条件，反之亦然。