Adaptive Evolution of Color Vision

生物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 结构和函数的数组。我们研究的长期目标是阐明驱动 这些在分子和功能水平上的适应性变化。我们计划使用VISION来实现这一目标 作为一个模范系统。在传统的光转化观点中，不仅氨基酸(AA)位点。即 参与视觉色素的光谱调谐，这些色素不仅位于“视网膜结合袋”内或其附近，而且 它们主要以一种附加的方式调节视觉色素的最大吸收波长(Xmax)。 然而，现在很明显，这两个“假设”在本质上都不成立。因此，要确定所有关键的AA 改变和了解它们对xmax-Shift的个体和协同效应，一些新的方法 必须被夺走。只有当我们建立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被完全理解。 本研究拟克隆五种深海鱼类(S. Leucepsarus)、松下巴(A.scintillans)、叉尾鱼(L.fitchf)、刺头鱼(S.altivelis)和金枪鱼(C. 通心粉)。然后我们将研究光谱调谐的分子基础和自适应的机制。 视觉色素在多种脊椎动物中的进化。生活在不同的深度，从 在200到4000米的高度，深海鱼类在~480纳米处接受不同程度的阳光。此外，淡水鱼 Viperish在~480 nm处发射生物发光，而Losebew在~480和~700 nm处发射生物发光。我们计划探索 视觉色素的三个特征：1)视觉光谱调谐的分子和化学基础 色素；2)正选择AA变化的统计和实验分析；以及3)共同进化 五种深海鱼类中每一种都含有类似的色素。在理论上使用计算方法 化学，我们计划测试光谱调谐的四个具体假设，并通过以下方式确定化学原理 测定了视觉色素的哪些吸收光谱。来测试人类的进化模式 在每个物种中，不同的并列配色根据光的分布而同步 栖息地，我们将比较核苷酸(或AA)替换和复制的进化速度 A和(3个珠蛋白基因在同一物种中，也将被克隆和测序。

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.