GENETIC ANALYSIS OF RETINAL DEGENERATION IN DROSOPHILA

果蝇视网膜变性的遗传分析

• 批准号: 3263472
• 负责人: JOSEPH E O'TOUSA
• 金额: $ 12.96万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3263472
• 关键词: Drosophilidae; alleles; cellular pathology; chimeric proteins; complementary DNA; congenital eye disorder; cytogenetics; electrophysiology; endonuclease; gel electrophoresis; gene expression; gene mutation; genetic library; genetic manipulation; genetic mapping; in situ hybridization; molecular cloning; molecular genetics; molecular pathology; retina degeneration; rhodopsin; visual photoreceptor

Specific genetic defects are responsible for a variety of retinal degeneration diseases that affect human populations. The goal of this research program is to characterize analogous defects in the invertebrate Drosophila melanogaster. In Drosophila, it is possible to combine molecular, genetic, physiological techniques to gain a better understanding of the altered cellular activities that underlie these diseases. Many Drosophila mutants previously identified by their effects on the process of visual transduction also show defects in photoreceptor maintenance. Mutants in the gene coding for the visual pigment rhodopsin show an age dependent loss of the microvillar membranes that form the rhabdomere of the photoreceptors. A large sample of defined mutants in the rhodopsin protein have been generated: these are likely to affect the stability of the protein, the potential of the protein to be glycosylated, or the positioning of the protein in the membrane. An immunohistochemical approach will investigate the mechanisms by which these rhodopsin mutants affect rhabdomere structure. Each of these mutant rhodopsins also will be - expressed in an in-vitro system to investigate the inherent stability and retinal binding capacity of the modified rhodopsin proteins. A newly identified gene, mda, plays a critical role in the structure and function of the photoreceptors. Mutants in this gene are defective in visual transduction and also show disarranged microvillar structures on the cytoplasmic face of the rhabdomeres. This region is the subcellular site of rhabdomeric membrane renewal and also likely the location of molecular events underlying the phototransduction response. Molecular characterization of this gene will address the role of the encoded gene product in photoreceptor maintenance and function. rdgC has a mutant phenotype that is similar to the inherited retinal degeneration syndromes that affect human populations. That is, there is no obvious defect in visual processes before the onset of retinal degeneration. Light stimulation of rhodopsin triggers degeneration in rdgC mutants. Therefore, the rdgC gene product acts to prevent retinal degeneration that occurs as a consequence of normal rhodopsin activity not directly involved in the phototransduction pathway. To deduce the normal function of the rdgC protein in photoreceptors, we will use molecular techniques to characterize the rdgC gene and gene product. Genetic strategies will be used to identify additional components that act in concert with rdgC to maintain photoreceptor structure.

特定的遗传缺陷是导致各种视网膜病变的原因。 影响人类的退化性疾病。这个目标 研究计划是描述无脊椎动物中类似的缺陷， 果蝇在果蝇中，有可能将联合收割机 分子、遗传、生理学技术来更好地了解 这些疾病背后的细胞活动的改变。 许多果蝇突变体以前通过它们对细胞的影响而被鉴定出来。 视觉信号转导过程也表现出感光细胞的缺陷 上维护编码视色素视紫红质的基因突变 显示了形成微绒毛膜的年龄依赖性损失， 光感受器的横纹肌。一个大样本的定义突变体在 视紫红质蛋白已经产生：这些可能会影响 蛋白质的稳定性，蛋白质被糖基化的可能性， 或蛋白质在膜中的定位。免疫组织化学 方法将调查这些视紫红质突变体的机制， 影响横纹肌结构。每一种突变的视紫红质也会- 在体外系统中表达以研究固有稳定性， 修饰的视紫红质蛋白的视网膜结合能力。 一个新发现的基因，mda，在结构中起着关键作用， 光感受器的功能。该基因的突变体在以下方面有缺陷： 视觉传导，也显示了在细胞膜上无序的微绒毛结构。 横纹肌的胞质面。这个区域是亚细胞部位， 横纹肌细胞膜的更新，也可能是分子的位置， 事件背后的光转导反应。分子 该基因的特征将解决编码基因的作用， 产品在感光体的维护和功能。 rdgC具有类似于遗传性视网膜色素变性的突变表型。 影响人类的退化综合征。即没有 视网膜病变发作前视觉过程明显缺陷 退化视紫红质的光刺激触发rdgC的变性 变种人因此，rdgC基因产物起到防止视网膜病变的作用。 由于正常视紫红质活性而发生的变性， 直接参与光传导途径。推导出法线 rdgC蛋白在光感受器中的功能，我们将使用分子 技术来表征rdgC基因和基因产物。遗传 战略将用于确定其他组件， 协同rdgC维持感光细胞结构。