MOLECULAR CHARACTERIZATION OF THE RHODOPSIN GENE

视紫红质，视紫红质是视杆细胞外段的主要膜蛋白 光感受器细胞，启动相关事件的复杂级联 在视觉过程中，通过吸收一个光子的光。这个 视紫红质基因两种结构特征的关系 以及调节其表达的分子机制，对人的生存 光感受器细胞是一个重要的神经生物学问题。 人们对此知之甚少。在小鼠视网膜中，纯合子的存在 视网膜变性缓慢)突变与a)有关 视紫红质缺乏97%的正常量；b)视杆细胞功能衰竭 要发育的外部节段；以及c)基因编程的早熟细胞 视杆感光细胞死亡。杂合子(rds/+)只有一半 视紫红质水平正常，形态变短变少 组织良好的棒材外段。总而言之，这些数据表明 Rds突变是一种“顺式作用”的调控基因，与 视紫红质基因或它实际上是在视紫红质的结构基因内。 我们的总体目标是定义和表征视紫红质基因和 它在正常和rds小鼠发育过程中的表达。我们构建了一个 小鼠视网膜c DNA表达文库的克隆及部分测序 视紫红质基因，并获得了单抗和单特异性抗体 对抗视紫红质。我们现在建议：a)描述两者的特征 通过Northern和Western的定性和定量分析， 视紫红质基因产物(mRNA和视蛋白)在正常、 杂合子和rds小鼠；b)克隆和测序 正常小鼠和rds小鼠的基因组文库；以及c)确定染色体 小鼠视紫红质基因的Southern定位和精确定位 中国仓鼠体细胞的限制性内切酶片段分析 杂交染色体组和重组近交系小鼠。这个 其他视网膜特异基因的表达也将按顺序进行监测 目的研究RDS基因突变的生化表型。 感光细胞的发育和退化。所获得的结果 本研究对遗传性失明的研究具有重要意义 (例如，视网膜色素变性)，并将为研究提供哺乳动物模型 与基因控制有关的确切分子事件 中枢神经系统中一组独特的神经元的退化 系统。

Rhodopsin, the major integral membrane protein of the rod outer segment of photoreceptor cells, initiates the complex cascade of events associated with the process of vision, by the absorption of a photon of light. The relationship of both the structural characteristics of the rhodopsin gene and the molecular mechanisms regulating its expression, to the survival of photoreceptor cells is an important neurobiological problem about which relatively little is known. In the mouse retina, the homozygous presence of the rds (retinal degeneration slow) mutation is associate with a) the absence of 97% of the normal amounts of rhodopsin; b) the failure of rod outer segments to develop; and c) the genetically programmed premature cell death of rod photoreceptor cells. The heterozygote (rds/+) has only half the level of rhodopsin as normal and has morphologically shorter and less well organized rod outer segments. Collectively, these data indicate that the rds mutation is either a "cis acting" regulatory gene adjacent to the rhodopsin gene or it is actually within the structural gene for rhodopsin. Our overall objective is to define and characterize the rhodopsin gene and its expression during development in normal and rds mice. We constructed a mouse retinal cDNA expression library, cloned and partially sequenced mouse rhodopsin cDNA and have obtained monoclonal and monospecific antibodies against rhodopsin. We are now proposing to: a) characterize both qualitatively and quantitatively by Northern and Western alalysis, the rhodopsin gene products (mRNA and opsin) during development of normal, heterozygote and rds mice; b) clone and sequence the rhodopsin gene from genomic libraries of normal and rds mice; and c) determine the chromosomal assignment and the exact locus of the mouse rhodopsin gene using Southern Analysis of restriction fragments from a mouse-Chinese hamster somatic cell hybrid chromosome panel and from recombinant inbred lines of mice. The expression of other retina specific genes will also be monitored in order to characterize the biochemical phenotype of the rds mutation during the development and degeneration of photoreceptor cells. The results obtained from this study will have importance for the study of hereditary blindness (e.g. retinitis pigmentosa) and will provide a mammalian model for studying the exact molecular events associated with genetically controlled degeneration of a unique population of neurons, in the central nervous system.