RETINOSCHISIS--GENETIC LINKAGE AND POSITIONAL CLONING

视网膜劈裂--遗传连锁和位置克隆

• 批准号: 2164001
• 负责人: PAUL A SIEVING
• 金额: $ 22.08万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-30 至 1996-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2164001
• 关键词: Muller's cell; artificial chromosomes; cellular pathology; complementary DNA; congenital vision disorder; developmental genetics; electroretinography; eye disorder diagnosis; family genetics; gene deletion mutation; gene rearrangement; genetic disorder diagnosis; genetic library; genetic markers; human genetic material tag; human subject; linkage mapping; macular degeneration; male; molecular cloning; phenotype; polymerase chain reaction; restriction fragment length polymorphism; retina detachment; sex linked trait

Our goal is to understand further the genetic and development basis of human X-linked juvenile retinoschisis (RS) (#31270 in McKusick, 1992) and the biology of Muller cells (retinal glial cells) that are believed to be involved in RS. This proposal presents the positional cloning strategy that we are using to identify and clone the RS gene. Retinoschisis causes significant loss of vision from a young age from macular cysts that are present at birth. In the peripheral retina the inner layers peep from the outer layers peel from the outer layers like sheets of tissue paper and can lead to unrepairable retinal detachment. The carrier state is not detectable, and cloning the RS gene will immediately benefit genetic counseling. The biological importance of RS extends beyond the clinical implications and involves elucidating mechanisms of retinal pathology presumed to be caused by Muller cell dysfunction. RS presents a unique opportunity to study inner retinal pathophysiology, since, unlike most other human inherited retinal dystrophies that affect the outer retinal layers, RS affects the proximal retina. In later age, RS males typically show secondary atrophy of the retinal pigment epithelium, and RS may provide insight into mechanisms important for dry forms of Age-Related Macular Degeneration. Muller cells impart structural integrity to the retina and mediate the retinal extracellular ionic homeostasis that is critical for function and survival of retinal neurons. Understanding the genetic and biological basis of RS holds promise of new understanding of basic mechanisms important for vision and retinal function. Our preliminary RS genetic study involved linkage with seven large families for which flanking RFLP markers were identified in p22.1-p22.3 (Sieving et al, 1990). We have now collected DNA from 35 RS pedigrees that include 102 affected males and more than 250 scorable meioses. We are cloning a portion of Xp22.1-22.3 into YAC contigs, preparatory to elaborating a micro-scale genetic and physical map around the RS locus. This project participants in the Michigan Human Genome Initiative Center which provides access to specialized technical support and resources. We have screened YAC libraries at the Michigan Genome Center using the RFLP marker closest to RS and have obtained four different YAC clones which we are now characterizing to construct a YAC contig around RS. We will then screen the contig for new microsatellite markers for genetic testing against RS. We are laos using a candidate gene approach by testing cDNAs in the RS region from a human retinal library enriched for X-chromosomal cDNAs.

我们的目标是进一步了解 与人X连锁的少年视网膜（RS）（McKusick，1992年的＃31270）和 据信，穆勒细胞（视网膜神经胶质细胞）的生物学 参与卢比。 该提议提出了位置克隆 我们用来识别和克隆RS基因的策略。 视网膜造成了从小就从 出生时存在的黄斑囊肿。 在外围视网膜中 内层从外层窥视外层剥离 薄纸片，可能导致无法修复的视网膜脱离。 载体状态无法检测到，克隆RS基因将会 立即受益于遗传咨询。 RS的生物学重要性超出了临床意义 并涉及阐明是视网膜病理的机制 由Muller细胞功能障碍引起。 RS提供了一个独特的机会 研究内部视网膜病理生理学，因为与大多数其他人不同 影响外视网膜层RS的遗传性视网膜营养不良 影响近端视网膜。 在以后的年龄，RS男性通常显示 视网膜色素上皮和RS的次生萎缩可能会提供 对与年龄相关黄斑的干燥形式重要的机制的洞察力 退化。 穆勒细胞赋予视网膜结构完整性 介导视网膜细胞外离子稳态至关重要 视网膜神经元的功能和存活。 了解遗传和 RS的生物学基础有望对基本的新理解 机制对于视力和视网膜功能很重要。 我们的初步RS遗传研究涉及与七个大型 在P22.1-P22.3中确定了侧翼RFLP标记的家庭 （Sieving等，1990）。 我们现在从35 RS的血统中收集了DNA 其中包括102名受影响的男性和超过250多名可记分的Meioses。 我们 将一部分XP22.1-22.3克隆到YAC重叠群中，准备为 详细说明RS基因座周围的微尺度遗传和物理图。 密歇根人类基因组倡议中心的该项目参与者 它提供了专门的技术支持和资源的访问权限。 我们已经使用The Michigan基因组中心筛选了YAC图书馆 RFLP标记物最接近RS，并获得了四个不同的YAC克隆 我们现在正在表征围绕Rs构建YAC重叠群。 我们 然后，将筛选新的微卫星标记的重叠群以进行遗传 针对Rs进行测试。 我们是老挝使用候选基因方法 从人类视网膜图书馆中测试RS区域中的cDNA X染色体cDNA。