Woodruff R I, Tilney L G
Department of Biology, West Chester University, West Chester, Pennsylvania, 19383-8102, USA.
Dev Biol. 1998 Aug 1;200(1):82-91. doi: 10.1006/dbio.1998.8948.
In the epithelium of Drosophila ovarian follicles, cytoplasm-filled intercellular bridges connect epithelial cells. This study presents further descriptive information about the morphology of these intercellular bridges and the extent of their distribution. We also offer speculations concerning the possible developmental importance of the epithelial bridges. These bridges, whose luminal diameters averaged 0.25 microm, are smaller than those forming the ring canals joining germline cells: nor do they increase their size over time. The membranes limiting the bridges are lined on the cytoplasmic side with an electron-dense material to which is attached a monolayer of filaments which encircle the bridge. By decoration with the S1 fragment of myosin, these filaments are confirmed as actin filaments. Following disruption of gap junctional dye coupling by treatment with 1 mM octanol, microinjection of Lucifer yellow CH revealed the extent and distribution of follicle cell intercellular bridges to be confined to arrays of no more than eight cells/cluster, with many such independent clusters comprising the epithelium. Thus cell-to-cell movement throughout the epithelium of cytosolic regulatory molecules cannot occur via these intercellular bridges. However, weak signals affecting only one or a few cells in each cluster would be amplified throughout the group by spread through the intercellular bridges.
在果蝇卵巢卵泡的上皮组织中，充满细胞质的细胞间桥连接着上皮细胞。本研究提供了关于这些细胞间桥形态及其分布范围的更多描述性信息。我们还对上皮桥可能的发育重要性进行了推测。这些桥的管腔直径平均为0.25微米，比连接生殖系细胞的环管形成的桥要小，而且它们的大小也不会随时间增加。限制这些桥的膜在细胞质一侧衬有电子致密物质，在该物质上附着有围绕桥的单层细丝。通过用肌球蛋白的S1片段进行标记，证实这些细丝为肌动蛋白丝。在用1 mM辛醇处理破坏间隙连接染料偶联后，荧光黄CH的显微注射显示卵泡细胞间桥的范围和分布局限于每组不超过八个细胞的阵列，许多这样独立的阵列组成了上皮组织。因此，胞质调节分子在整个上皮组织中的细胞间移动不可能通过这些细胞间桥发生。然而，仅影响每个阵列中一个或几个细胞的微弱信号会通过细胞间桥在整个组中扩散而被放大。
