Membrane Traffic and Topography

据推测，细胞内的细胞内膜运输需要小囊泡，这些小囊泡在细胞的固定内膜区室之间穿梭。 这种囊泡被认为以矢量方式携带内容物，并在递送后将膜材料返回到起始点。 尽管经常被假设，但很少有形态学证据表明这些是真实的。将利用冷冻电子显微镜来尝试观察草履虫中的此类囊泡。 冷冻固定将用于超快速地物理固定细胞，因此可以保留裂变或融合的中间步骤。 随后的冷冻替代或深蚀刻旋转阴影步骤将允许在接近天然状态下观察细胞内部，从而可以定位小运输或穿梭囊泡。 单克隆抗体组织化学将用于鉴定穿梭囊泡的膜成分。 这些研究将提供有关细胞内膜和膜成分运动的新信息。

Intracellular membrane traffic in cells has been postulated to require small vesicles which shuttle between fixed endomembrane compartments of the cell. Such vesicles are thought to carry contents in a vectorial manner and return membrane material to the point of origin after delivery. Though often postulated, little morphological evidence has been forthcoming to show that these are real. Cryoelectron microscopy will be utilized to attempt to visualize such vesicles in Paramecium. Cryofixation will be used to physically fix cells ultrarapidly so intermediate steps in fission or fusion can be preserved. Subsequent cryosubstitution or deep-etch rotary-shadow steps will allow observation of the cell interior in a nearly native state, making it possible to locate small transport or shuttle vesicles. Monoclonal antibody histochemistry will be used to identify membrane components of the shuttle vesicles. These studies will provide new information on the movements of membranes and membrane components within cells.