GENES AND VISUAL PIGMENTS OF RED-GREEN COLOR VISION

这项研究的长期目标是了解 视觉的生物学基础 这项建议的近期目标是 确定X连锁基因的基本特性， 颜料. 为此，具体目标是： 1.为了确定（i）在细胞上的视色素基因的数量， X染色体，（ii）编码长波长的基因的数量 敏感色素，和（iii）基因的间隔和排列 编码中长波长敏感色素。 2.描述构成原始异常颜色的锥状色素 视觉，以确定基因的结构， 色素异常，并研究遗传机制， 产生异常色素。 一个解释红绿色分子遗传基础的模型 由Nathans等人（Science 232：198-202，1986）阐述人类视觉已经 获得了广泛的认可。 这一模式的主要特点包括：（一） X染色体上的视觉色素基因的平均数量是 约三个和（ii）所有具有正常色觉的个体 有一个单一的长波长敏感锥色素基因。 但 现有的数据并不支持Nathans的这些和其他基本方面 等理论。 本研究的意义在于， 对视觉的分子生物学的理解必须建立在一个 关于基因最基本特性的事实基础， 编码锥状色素。 解释个体的理论 正常色觉的差异，常见的颜色缺陷，以及更罕见的 使人衰弱的视觉缺陷，以及旨在测试 这些理论，将严重依赖于知道的可能性， 色素基因的数量，产生色素的基因的种类， 不同的色素，这些基因的相对频率及其 安排 对这些基本事实的了解可以指导对 理解的不只是锥的性质--它们的谱 敏感性和它们的比例--这是人类多样性的基础 视觉，也是处理视觉信息的电路 起来。 X-连锁锥色素基因的基本特征 将通过以下方法研究视力正常和色觉缺陷的男性： Southern杂交分析和基因组DNA将用于 聚合酶链反应扩增X连锁视觉细胞的片段 色素基因的核苷酸序列分析。 色觉和 受试者的视觉敏感度将使用 心理物理学方法和视网膜电图。

The long term goal of this research is to understand the molecular biologic basis of vision. The immediate goal of this proposal is to determine the fundamental properties of X-linked genes that encode cone pigments. To that end the specific aims are: 1. To determine (i) the number of visual pigment genes on the X-chromosome, (ii) the number of genes that encode long-wavelength sensitive pigments, and (iii) the spacing and arrangement of genes encoding middle and long wavelength sensitive pigments. 2. To characterize the cone pigments that underlie protanomalous color vision, to determine the structure of the genes that produce protanomalous pigments, and to investigate the genetic mechanisms that give rise to anomalous pigments. A model to explain the molecular genetic basis of red-green human vision formulated by Nathans et al. (Science 232:198-202, 1986) has gained wide acceptance. Key features of this model include that (i) the average number of visual pigment genes on the X-chromosome is approximately three and (ii) all individuals with normal color vision have a single long wavelength sensitive cone pigment gene. However, the available data do no support these and other basic aspects of the Nathans et al. theory. The significance of the research proposed here is that an understanding of the molecular biology of vision must be built from a base of facts about the most fundamental properties of the genes that encode the cone pigments. Theories conceived to explain the individual differences in normal color vision, common color defects, and rarer more debilitating visual defects, as well as the experiments designed to test those theories, will depend critically on knowing the possibilities allowed by the number of pigment genes, the variety of genes producing different pigments, the relative frequencies of those genes and their arrangements. Knowledge of these basic facts can guide the search for understanding of riot only the properties of the cones--their spectral sensitivities and their ratios--that underlie the diversity of human vision, but also of how the circuits for processing visual information arise. The basic features of the X-linked cone pigment genes from males with normal and color defective vision will be investigated by Southern hybridization analysis and genomic DNA will be used in the polymerase chain reaction to amplify segments of the X-linked visual pigment genes for nucleotide sequence analysis. The color vision and visual sensitivity of the subjects will be examined in detail using psychophysical methods and the electroretinogram.