MOLECULAR MECHANISMS IN RETINAL DEGENERATIONS

这项提案的长期目标是表征染色体 绘制并分离可能与遗传性视网膜病变有关的基因， 影响动物和人类的退化。 基因知识 可能会增加我们对 发病过程，此外，它可能有助于发展 研究如何控制甚至阻止异常的表达， 基因. 首先研究视网膜变性的rd小鼠模型。 基本策略包括开发一种新的探针， 光受体富集的cDNA，这将允许选择低 从正常小鼠视网膜cDNA中获得大量光感受器特异性克隆 图书馆 这些克隆将重新筛选与探针组成的rd 成人视网膜cDNA和rd 9-11天视网膜cDNA以精确定位rd 候选基因 经过北方分析发展中国家的研发和正常 小鼠视网膜RNA与rd候选cDNA进行比较，以确定任何 rd和正常mRNAs之间的差异，小鼠染色体 将确定每个潜在rd cDNA的位置，如果 5号染色体，其在该染色体内的特定位置将是 确立了习 核苷酸和还原的氨基酸序列以及 RD候选基因的基因组结构及其体外研究 然后将确定转录和翻译。 最终证明 用克隆的基因鉴定RD基因将需要校正 rd表型 涉及转基因小鼠的实验将计划用于 但不在本申请的范围内。 分离的光感受器特异性cDNA将用于人类研究， 在受影响的家庭中寻找RFLPs模式的改变， 任何一种不同类型的色素性视网膜炎。 为了开展拟议的工作，目前在分子生物学中使用的方法 生物学将被使用。 这些研究将增加对 正常和异常视网膜的分子特性，因为除了 RD基因可以表征其它光感受器特异性基因。

The long-term objective of this proposal is to characterize, chromosome map and isolate genes that may be involved in inherited retinal degenerations affecting animals and humans. Knowledge about the genes that are responsible for these diseases may increase our understanding of the process of pathogenesis and in addition, it may help to develop studies on how to control or even arrest the expression of the abnormal genes. The rd mouse model of retinal degeneration will be studied first. the basic strategy involves the development of a novel probe consisting of photoreceptor-enriched cDNAs which will allow selection of low abundance photoreceptor-specific clones from a normal mouse retinal cDNA library. These clones will be re-screened with probes consisting of rd adult retinal cDNAs and rd 9-11 day-old retinal cDNAs to pinpoint rd candidate genes. After Northern analysis of developing rd and normal mouse retinal RNAs with the rd candidate cDNAs to determine any differences between the rd and normal mRNAs, the mouse chromosome location of each potential rd cDNA will be determined and, if on chromosome 5, its specific position within this chromosome will be established. the nucleotide and reduced amino acid sequences as well as the genomic organization of the rd candidate genes and their in vitro transcription and translation will then be determined. Final proof of the identify of the rd gene with cloned gene will require correcting the rd phenotype. Experiments involving transgenic mice will be planned for the future but are not within the scope of this application. Isolated photoreceptor-specific cDNAs will be used in human studies to search for alterations in the patterns of RFLPs in families affected with any of the different types of retinitis pigmentosa. To carry out the proposed work, methods currently used in Molecular Biology will be employed. These studies will add to the knowledge of the molecular properties of normal and abnormal retinas since in addition to the rd gene other photoreceptor-specific genes may be characterized.