MOLECULAR MECHANISMS IN RETINAL DEGENERATIONS

这项提议的长期目标是确定染色体的特征 定位和分离可能与遗传性视网膜有关的基因 影响动物和人类的退化。关于基因的知识 对这些疾病负责的人可能会增加我们对 发病的过程，此外，它可能有助于发展 关于如何控制甚至阻止异常表达的研究 基因。首先将研究视网膜变性的RD小鼠模型。 基本战略包括开发一种新的探头，包括 光感受器丰富的cDNA将允许选择Low 正常小鼠视网膜中丰富的光感受器特异性克隆 图书馆。这些克隆将用由RD组成的探针进行重新筛选 成人视网膜cDNA和9-11日龄视网膜cDNA用于精确定位RD 候选基因。经过北向分析发展中的RD和正常 用小鼠视网膜RNA和RD候选cDNA来确定 RD和正常mRNAs、小鼠染色体的差异 将确定每个潜在RD cDNA的位置，如果在 5号染色体，它在这条染色体中的特定位置将是 已经成立了。核苷酸和还原氨基酸序列以及 RD候选基因的基因组组织及其体外研究 然后将确定转录和翻译。最终证明 将RD基因与克隆的基因进行鉴定，需要纠正 RD表型。利用转基因小鼠的实验将被计划用于 但不在本申请的范围内。 分离的光感受器特异的cDNA将用于人体研究 寻找受影响的家庭中RFLP模式的改变 任何一种不同类型的视网膜色素变性。 为了开展拟议的工作，目前在分子生物学中使用的方法 生物学将会被使用。这些研究将增加对 正常和异常视网膜的分子特性 RD基因和其他光感受器特异性基因也可能被鉴定出来。

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.