Ultrastructure

核心D将执行支持所有其他项目所必需的定性和定量组织学和超微结构检查。该核心不仅将提供电子、相位对比和共聚焦显微镜的各种技术，而且它还将以高标准运行，并对实验和分子变化的结果提供专家关键评估。统一和一致地使用高质量图像将允许检测到蛋白质-蛋白质相互作用和单个细胞器的反应中的细微变化，这些细胞器要么是功能改变的基础，要么是这种改变的长期结果。很明显，肌肉纤维对影响兴奋-收缩偶联的突变的总体超微结构反应是相当特异的，并提供了相当大的对病因影响的洞察力。在过去的一段时间里，我们已经证明了这种病理对纤维类型和性别的强烈依赖性，这与功能上的相似变化很好地对应。提出了两种通用的方法。一个是在突变的背景下定义钙释放单位(CRU，骨骼肌中的三联体)的主要蛋白质成分之间的关系的任何变化，另一个是通过发育和衰老跟踪病理的发展(最具体地说是线粒体、肌原纤维和CRU的变化)，以及与突变对CRU通道的已知功能影响有关的变化。这将通过结合光学显微镜技术(纤维整体的相位对比度和荧光免疫标记纤维的共聚焦成像)与电子显微镜的薄切片和冷冻断裂以及定量形态计量技术来实现。该核心旨在确定每个突变在短期内对钙释放单位的大分子组装的主要影响，以及长期对SR、线粒体和收缩物质的次要影响。

Core D will perform the qualitative and quantitative histological and ultrastructural checks that are necessary to support all other Projects. The Core will not only supply various techniques of electron, phase contrast and confocal microscopy, but it will also operate at a high standard of quality and offer an expert critical evaluation of the results of experimental and molecular alterations. The uniform and consistent use of high quality images will allow the detection of even subtle alterations in protein-protein interactions and in the response of individual cell organelles that either are at the basis of altered functions or are the long term results of such alterations. It is clear that the overall ultrastructural response of the muscle fiber to mutations affecting excitation-contraction coupling are quite specific and offer considerable insight into causative effects. In the past period we have evidenced a strong fiber type- and gender-dependence of the pathology, that correspindes quite well with similar variations in function. Two general approaches are proposed. One is to define any alterations in the relationships between the major protein components of calcium release units (CRUs, triads in skeletal muscle) within the context of the mutation and the other is to follow the development of pathology (most specifically mitochondrial, myofibrillar and CRUs' alterations) through development and aging and in relation to the known functional effects of the mutation on CRUs' channels.This will be achieved by combining light microscope techniques (phase contrast of fibers whole mounts and confocal imaging of fluorescently immunolabeled fibers) with thin sectioning and freeze-fracture for electron microscopy supplemented by quantitative morphometry techniques. The core aims at defining the primary impact of each mutation on the macromelcular assembly of calcium release units within a short term and the secondary impact on SR, mitochondria and contractile material on the long term.