GENES AND VISUAL PIGMENTS OF RED-GREEN COLOR VISION

这项研究的长期目标是了解分子 视觉的生物学基础。这项提议的直接目标是 确定编码锥体的X连锁基因的基本性质 颜料。为此，具体目标是： 1.测定(I)视色素基因的数量 X染色体，(Ii)编码长波的基因数量 敏感色素，以及(Iii)基因的间距和排列 对中长波敏感颜料进行编码。 2.确定构成蜂窝状颜色的锥体色素的特征 视觉，以确定产生 亲肿瘤色素，并研究遗传机制 会产生异常的色素。 一种解释红绿色分子遗传基础的模型 Nathans等人提出的人类视觉。(Science 232：198-202,1986) 得到了广泛的认可。这种模式的主要特点包括：(I) X染色体上视觉色素基因的平均数是 大约三个和(Ii)所有色觉正常的人 具有单一长波长敏感的锥体色素基因。然而， 现有数据不支持纳桑人的这些和其他基本方面 等人的研究。理论。 这里提出的研究的意义是，一个 对视觉分子生物学的理解必须建立在 关于基因最基本属性的事实基础 对锥形颜料进行编码。用来解释个体的理论 正常色觉的差异，常见的颜色缺陷，以及更罕见的 令人衰弱的视觉缺陷，以及旨在测试 这些理论将在很大程度上取决于对 允许色素基因的数量，产生的基因的多样性 不同的色素，这些基因和它们的相对频率 安排好了。对这些基本事实的了解可以指导对 只了解锥体的性质--它们的光谱 敏感度及其比率--人类多样性的基础 视觉，还有处理视觉信息的电路 站起来。 杨树X-连锁锥体色素基因的基本特征 视力正常和色觉有缺陷的男性将接受 Southern杂交分析和基因组DNA将用于 聚合酶链式反应扩增X连锁视觉片段 用于核苷酸序列分析的色素基因。色觉和 受试者的视觉敏感度将通过 心理物理方法和视网膜电信号。

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.