Clermont Y, Rambourg A, Hermo L
Department of Anatomy and Cell Biology, McGill University, Montréal, Quebec, Canada.
Anat Rec. 1995 Jul;242(3):289-301. doi: 10.1002/ar.1092420302.
The trans-Golgi network (TGN) is generally considered as a distinct and permanent structural compartment of the Golgi apparatus of various cell types. To verify this postulate we examined and compared the three-dimensional characteristics of the TGNs of 14 different mammalian cell types as presented in our various publications since 1979 when we initially described the trans-tubular network of Sertoli cells.
In all these studies we used low and high voltage electron microscopes on thin or thick sections of tissues fixed with glutaraldehyde and postfixed with reduced osmium. The sections were stained with uranyl acetate and lead citrate. Stereopairs, prepared from photographs of tilted specimens, permitted a direct observation of the three-dimensional structure of the various elements of the Golgi apparatus.
The TGNs are multilayered and extensive in cells which do not form large typical secretory granules (Sertoli cells, nonciliated cells of ductuli efferentes, spinal ganglion cells) but have an extensive lysosomal system. The TGN is absent in cells forming very large secretory granules (secretory cells of seminal vesicles and lactating mammary glands). The TGNs are small in cells producing small to medium-size secretory granules and/or appear as residual fragments on the trans aspect of the Golgi stacks (e.g., mucous cells of Brunner's gland, pancreatic acinar cells, etc.). In cells with multiple and extensive TGNs, a continuity of these tubular networks with the two or three transmost saccules of the stack is observed but there are seemingly no connections between the TGNs. Whenever the TGNs are present, they do not form a continuous structure along the Golgi ribbon. However, they do present, in all cases, configurations suggestive of desquamation and renewal.
The structure of the TGN varies considerably from one cell type to another, being extensive in cells not showing typical secretory granules but having an extensive lysosomal system, while in secretory cells showing small or large secretory granules the TGN is either small or even entirely absent.
反式高尔基体网络（TGN）通常被认为是各种细胞类型的高尔基体中一个独特且永久的结构区室。为了验证这一假设，我们检查并比较了14种不同哺乳动物细胞类型的TGN的三维特征，这些特征来自我们自1979年最初描述支持细胞的反式管状网络以来的各种出版物。
在所有这些研究中，我们使用了低电压和高电压电子显微镜，观察用戊二醛固定并用还原锇后固定的组织的薄切片或厚切片。切片用醋酸铀和柠檬酸铅染色。从倾斜标本的照片制备的立体对允许直接观察高尔基体各种元件的三维结构。
在不形成大型典型分泌颗粒的细胞（支持细胞、输出小管的无纤毛细胞、脊髓神经节细胞）中，TGN是多层且广泛的，但具有广泛的溶酶体系统。在形成非常大的分泌颗粒的细胞（精囊分泌细胞和泌乳乳腺细胞）中不存在TGN。在产生小至中等大小分泌颗粒的细胞中，TGN较小，和/或在高尔基体堆叠的反面表现为残余片段（例如，布鲁纳腺的粘液细胞、胰腺腺泡细胞等）。在具有多个且广泛的TGN的细胞中，观察到这些管状网络与堆叠的最外侧两到三个囊泡连续，但TGN之间似乎没有连接。每当存在TGN时，它们不会沿着高尔基体带形成连续结构。然而，在所有情况下，它们确实呈现出提示脱屑和更新的形态。
TGN的结构在不同细胞类型之间有很大差异，在不显示典型分泌颗粒但具有广泛溶酶体系统的细胞中广泛存在，而在显示小或大分泌颗粒的分泌细胞中，TGN要么小，要么甚至完全不存在。
