EVOLUTIONARY GENETICS OF VERTEBRATE VISION

视觉通过影响生物的进化对生物的进化产生深远的影响 通过选择配偶和觅食等基本行为生存 战略。它的重要性从视觉的存在中得到了强烈的体现 从细菌到人类的一系列有机体中的色素。 在这里，我们建议继续我们的分子进化分析，使用 种类繁多：海洋七鳃鳗(Petromyzon Marinus)， 腔棘鱼，美洲变色龙(Anolis) Carolinens)和鸽子(Columba Livia)。利用这些物种，我们计划 研究人类免疫缺陷的分子遗传学机制 脊椎动物的模糊和有色视觉。 通过构建基因组DNA文库、克隆和核苷酸测序， 我们计划对这些物种的所有视蛋白基因进行表征。这些序列 和其他可用的视蛋白基因序列将受到广泛的 系统发育分析。从统计分析中，我们打算了解 视蛋白基因进化的过程，包括基因复制和 同源和同源视蛋白基因的功能分化 在脊椎动物中。使用从序列比较中收集的信息和 对自然发生的物种特有的最大波长的认识 吸光度(lambda-max)，我们还将确定潜在的重要 氨基酸(和核苷酸)取代可能导致 Lambda-max值。 发现的视蛋白基因将在培养的COS细胞中表达， 与11-顺式视网膜重组，并测量其吸收光谱 编码的视蛋白。唯一的核苷酸(和氨基酸)的作用 酸)替换将通过使用Site- 定向诱变并进行COS细胞表达实验。 通过这种方式，我们将严格评估具体的效果。 核苷酸替代对任何视蛋白功能的影响。

Vision has profound effects on the evolution of organisms by affecting survivorship through such basic behaviors as mate choice and foraging strategies. Its importance is strongly indicated by the presence of visual pigments in a whole array of organisms ranging from bacteria to human. Here, we propose to continue our molecular evolutionary analyses by using a diverse range of species: marine lamprey (Petromyzon marinus), coelacanth (Latemeria chalumnae), American chameleon (Anolis carolinensis), and pigeon (Columba livia). Using these species, we plan to investigate molecular genetic mechanisms that underlie the processes of dim and color visions in vertebrates. By constructing genomic DNA libraries, cloning and nucleotide sequencing, we plan to characterize all opsin genes from these species. These sequence and other available opsin gene sequences will be subjected to extensive phylogenetic analyses. From statistical analyses, we intend to learn the processes of the opsin gene evolution, including gene duplications and functional differentiations of the orthologous and paralogous opsin genes in vertebrates. Using information collected from sequence comparisons and knowledge of naturally-occurring species-specific wavelength of maximal absorptions (lambda-max), we will also identify the potentially important amino acid (and nucleotide) substitutions which may cause changes in the lambda-max values. The opsin genes found will be expressed in cultured COS cells, reconstituted with 11-cis-retinal, and measured for the absorption spectra of the opsins encoded. The effects of the unique nucleotide (and amino acid) substitutions will be investigated by generating mutants using site- directed mutagenesis and conducting the COS cell expression experiments. In this way, we will rigorously evaluate the effects of specific nucleotide substitutions on the functional changes of any opsin.