3 D RECONSTRUCTION OF MAMMALIAN GOLGI APPARATUS

高尔基体膜及其相关的结构细节 小泡仍未被定义。相邻区域之间的连续性 高尔基体素与跨高尔基体池的关系 以及与之相关的囊泡和小管网络(跨高尔基体 网络或TGN)未解决。我们正在通过以下方式解决这个问题 两种三维技术：(1)选择性染色和断层扫描；(2) 抗体或酶标记物，与薄或 超薄的连续切片。已经准备了10张断层照片 化学固定细胞(Ladinsky等人1994年)和5个来自快速冷冻的， 冷冻替代细胞。这些断层图像显示包被了一层。 囊泡和其他具有新的被毛形态的囊泡在 TGN。我们现在把注意力集中在快速修复的细胞上 冷冻和冷冻替代以获取有关膜的信息 用高质量方法保存的细胞中的排列。初步 对这些标本的研究证实了我们对不同 从TGN萌发的小泡的被毛形态和提示 高尔基体连续脑池之间的意外关系 堆叠。叠层之间和高尔基体之间的膜连续性问题 元素和内噬体体现在正在这个保存完好的 材料。高尔基体形态的几个新特征已经出现， 如许多池子上大小不一的隔板和 指状小管从内部池通过 窗在相邻的池中，进入TGN或CGN。我们还有 发现连接非紧凑结构的顺式和/或反式脑池 高尔基山脉的区域(见研究重点#1)。

The structural details of Golgi membranes and their associated vesicles are still undefined. Both the continuity between adjacent Golgi elements and the relationship between the trans-Golgi cisternae and theie associated network of vesicles and tubules (the Trans-Golgi Network, or TGN) are unresolved. We are approaching this problem with two 3-D technologies: (1) selective stains and tomography and (2) antibodies or enzymatic markers, in conjunction with thin or super-thin serial sections. Ten tomograms have been prepared from chemically fixed cells (Ladinsky et al. 1994) and 5 from fast-frozen, freeze-substituted cells. These tomograms reveal clathrin coated vesicles and other vesicles with a novel coat morphology forming in the TGN. We are now focusing our attention on cells fixed by rapid freezing and freeze-substitution to get information about membrane arrangements in cells preserved by high quality methods. Preliminary work with these specimens confirms our identification of different coat morphologies on vesicles budding from the TGN and suggests unexpected relationships among the successive cisternae in the Golgi stack. Issues of membrane continuity between stacks and between Golgi elements and endosomes are now being examined in this well preserved material. Several novel features of Golgi morphology have emerged, such as fenestrae of various sizes on many of the cisternae and finger-like tubules that project from an interior cisterna through a fenestra in an adjacent cisterna, into the TGN or CGN. We have also found cis and/or trans cisternae that connect across noncompact regions of the Golgi (See Research Highlight #1).