DYSTROGLYCAN FUNCTION IN DEVELOPING BASEMENT MEMBRANES

营养不良多糖是一种分子，它直接与 肌营养不良的病理基础，也许还有其他人类 疾病。然而，营养不良多糖的基本功能仍然存在 不清楚。抗肌营养不良蛋白基因敲除鼠标早期显示 Reichert膜缺陷的胚胎致死性表型 胚胎基底膜。详细的表型表明 假设营养不良糖链是装配所必需的 细胞外基质蛋白进入基底膜结构。 本提案中概述的实验就是为了测试这一点 假说是迈向理解 营养不良多糖的生物学作用。它的四个具体目标 建议：1)确定分子和细胞基础 抗肌营养不良基因敲除中赖氏膜缺陷的原因分析 胚胎；2)营养不良多聚糖在Reichert病中的作用分析 器官培养系统中的膜组件；以及，3)分析 类胚体中的基底膜组装 营养不良糖蛋白缺失的ES细胞。支持这些目标的实验 涉及营养不良糖蛋白基因敲除胚胎的原位分析，以及 使用细胞和器官培养模型来测试营养不良蛋白聚糖在 基底膜组件。因为基底膜是 正常组织结构和功能的基本特征， 了解营养不良多糖在其发育过程中的作用应该有 认识人类地下室疾病的重要性 膜，如肌肉营养不良症。

Dystroglycan is a molecule that is directly relevant to the pathology underlying muscular dystrophy and perhaps other human diseases. However, the basic function of dystroglycan remains unclear. The dystroglycan knockout mouse displays an early embryonic lethal phenotype with defects in Reichert's membrane- an embryonic basement membrane. The detailed phenotype suggests the hypothesis that dystroglycan is required for the assembly of extracellular matrix proteins into a basement membrane structure. The experiments outlined in this proposal are designed to test this hypothesis as a step toward the long term goal of understanding the biological role of dystroglycan. The four specific aims of this proposal are: 1) Determination of the molecular and cellular basis for the defect in Reichert's membrane in dystroglycan knockout embryos; 2) Analysis of the role of dystroglycan in Reichert's membrane assembly in an organ culture system; and, 3) Analysis of basement membrane assembly in embryoid bodies derived from dystroglycan-null ES cells. The experiments supporting these aims involve in situ analysis of dystroglycan knockout embryos, and the use of cell and organ culture models to test dystroglycan's role in basement membrane assembly. Since basement membranes are fundamental features of normal tissue structure and function, understanding dystroglycan's role in their development should have importance for understanding human disorders involving basement membranes, such as the muscular dystrophies.