HUMAN COLOR VISION--A MOLECULAR GENETIC ANALYSIS

拟议的研究针对的是对结构的定义 人类的视觉色素，以及如何理解这些 结构调节人类的色觉。更具体地说，我们希望测试 这三种视锥细胞中的视觉色素类似于 由脱辅基蛋白(视蛋白)共价组成的杆状罗多司宾 与常见的11顺式视网膜发色团有关，即 视觉色素之间的吸收光谱是由结构 视蛋白之间的差异，这些结构差异是由 多基因家族成员间的核苷酸序列差异 编码视蛋白，以及众所周知的颜色遗传变异 视觉是由编码锥体视蛋白的那些成员的突变造成的。 为此，我们建议克隆、分离和测序 编码两种正常人眼视色素的蛋白质部分 和突变的个体。从这些克隆的基因中，我们将产生 在适当的宿主载体系统中编码的蛋白质，将它们连接到 11-cis视网膜，并对重组视色素进行体外研究。这 方法应该允许对模型进行直接测试。详细分析了 许多突变体应该提供对分子结构和 视觉色素的作用机制，这对我们的 对视力及其病理异常的基本了解。我们的 策略是(I)在核苷酸水平上分离和鉴定 编码研究最好的视觉色素的基因，牛红螺旋体(II)使用 将该基因的编码序列作为杂交探针至少分离出 人类视蛋白基因之一(例如，人类视紫红质的基因)，来自 基因组DNA克隆文库，以及(Iii)类似地使用这样的人类基因 隔离以识别和隔离假设视神经的其他成员 人类的多基因家族。这项计划的第一步是 完美无缺。

The proposed research is directed toward a definition of the structure of the human visual pigments and toward an understanding of how these structures mediate human color vision. More specifically, we wish to test the model that the visual pigments in the three types of cones resemble the rhodospin of the rods in consisting of an apoprotein (opsin) covalently linked to the common 11-cis retinal chromophore, that differences in the absorption spectra among the visual pigments result from structural differences among the opsins, that those structural differences result from nucleotide sequence differences among the members of a multigene family encoding the opsins, and that the well known genetic variations in color vision result from mutations in those members that encode the cone opsins. To this end, we propose to clone, isolate and sequence the genes that encode the protein moieties of the human visual pigments fom both normal and mutant individuals. From these cloned genes we will produce the encoded proteins in appropriate host-vector systems, attach them to the 11-cis retinal and study the reconstituted visual pigments in vitro. This approach should allow a direct test of the model. Detailed analyses of many mutants should provide insights into the molecular structure and mechanism of action of the visual pigments that are important both to our basic understanding of vision and to its pathologic anomalies. Our strategy is (i) to isolate and characterize at the nucleotide level the gene encoding the best studied visual pigment, bovine rhodospin (ii) to use coding sequences from this gene as hybridization probes to isolate at least one of the human opsin genes ( e.g., that for human rhodopspin) from a library of genomic DNA clones, and (iii) to similarly use such a human gene isolate to identify and isolate other members of the postulated opsin multigene family in humans. The first step in this plan has been acccomplished.