RETINAL PATHOPHYSIOLOGY OF INFANTS AND ADULTS

描述（资助申请摘要）：视网膜色素变性（RP） 在美国是视力丧失的主要原因。 主 自设立以来，该基金的重点一直放在生理机制上 在儿童和年轻人中的杆损失。 本次更新中提出的研究 是由对潜在过程的理解的快速进步所推动的， 脊椎动物视杆细胞中的光传导。 初步结果显示， 光转导的激活和失活阶段可以在 视网膜电图（ERG）。 2000年完成的工作 前一个周期提供了有力的证据，表明a波的前沿 是定量描述的激活阶段的最新模型， 转导 我们将用一个双闪光范例来扩展这项工作， 转导的探针失活阶段。 这项工作将集中在病人身上 与我们庞大且快速增长的数据库中的已知突变进行比对 建议的ERG技术的应用将使我们能够确定 激活和失活的缺陷由特定的基因突变引起。 与Daiger博士进行拟议的研究的目标是确定 基因和突变导致常染色体显性RP（adRP）在这些患者。 拟议的测试有两个组成部分，第一，筛选突变， 视紫红质、外周蛋白/RDS和其他导致adRP的基因 第二，合适的adRP家族的连锁测试。 突变 筛选方法包括SSCP、裂解酶错配检测和基因组测序。 测序 将在具有6个或6个以上基因的adRP家族中进行连锁检测。 更多受影响的成员使用一组微卫星标记内或 邻近15个不同的基因座，导致adRP或相关疾病。 由这些 我们希望通过这些方法来确定超过50%的潜在遗传原因。 ADRP家族 转基因小鼠技术代表了一种强大的 表型-基因型因果关系的方法。 我们的技术 研究RP的激活和失活机制， 应用于小鼠模型。 我们将评估转基因的表型 在视网膜变性慢（rds）基因中表达突变的小鼠 与adRP相关，在视杆细胞外节蛋白1（ROM 1）敲除小鼠中， 在双基因L185 rds-/rds+，ROM 1-/ROM 1+小鼠中。 我们将决定 改变外节的脂质环境对 在这些RP动物模型中， 致病突变影响外节结构。

DESCRIPTION (Abstract from Grant Application): Retinitis pigmentosa (RP) represents a major cause of visual loss in the Untied States. The primary focus of this grant since its inception has been on physiological mechanisms of rod loss in children and young adults. Studies proposed in this renewal are motivated by rapid advances in the understanding of processes underlying phototransduction in vertebrate rods. Preliminary results suggest that both activation and inactivation stages of phototransduction can be evaluated in patients through the electroretinogram (ERG). Work completed in the previous cycle provides strong evidence that the leading edge of the a-wave is quantitatively described by a recent model of the activation stages of transduction. We will extend this work with a two-flash paradigm that probes inactivation stages of transduction. The work will focus on patients with known mutations from our large and rapidly growing database. Application of proposed ERG techniques will allow us to determine which defects in activation and inactivation result from specific gene mutations. The goal of the proposed subcontract with Dr. Daiger is to determine the genes and mutations causing autosomal dominant RP (adRP) in these patients. The proposed testing has two components, first, screening for mutations in rhodopsin, peripherin/RDS and other genes causing adRP as they are identified and, second, linkage testing of suitable adRP families. Mutation screening methods include SSCP, Cleavase mismatch detection and genomic sequencing. Linkage testing will be conducted in adRP families with 6 or more affected members using a panel of microsatellite markers within or adjacent to 15 distinct loci causing adRP or allied disorders. By these methods we expect to determine the underlying genetic cause in more than 50% of adRP families. Transgenic mouse technology represents a powerful approach to phenotype-genotype causal relations. The techniques we are developing for studying activation and inactivation mechanisms in RP can be applied to the mouse models. We will evaluate the phenotype of transgenic mice expressing mutations in the retinal degeneration slow (rds) gene associated with adRP, in rod outer segment protein 1 (ROM1) knockout mice, and in digenic L185 rds-/rds+, ROM1-/ROM1+ mice. We will determine whether modifying the lipid environment of the outer segment has an effect on the severity of degeneration in these animal models of RP where the disease-causing mutation affects outer segment structure.