Miething A
Anatomisches Institut der Universität Bonn, Germany.
Cell Tissue Res. 1995 Aug;281(2):359-65. doi: 10.1007/BF00583404.
The bridge-partitioning complex present in pre-existing intercellular bridges of dividing spermatogonia in the juvenile golden hamster testis was studied by electron microscopy. There is a close temporal adjustment in the appearance of this structure to those stages of mitosis during which the cells are without a nuclear membrane, i.e., the bridge-partitioning complex is formed at the transition between prophase and prometaphase and gradually disappears during telophase. In addition, in a certain form of degenerative dividing germ cells, which completely lack a bridge-partitioning complex in pre-existing intercellular bridges, condensed chromatin not surrounded by a nuclear membrane occasionally projects through these open bridges and thus may well change over to a neighboring cell of the same clone. These results strongly indicate an essential barrier function of the bridge-partitioning complex. It temporarily prevents intraclonal exchange of nuclear material during those stages of mitosis where a nuclear membrane is lacking and, thus, maintains genetic integrity of male germ cells during synchronous divisions.
通过电子显微镜研究了幼年金黄仓鼠睾丸中正在分裂的精原细胞预先存在的细胞间桥中存在的桥分隔复合体。该结构的出现与有丝分裂的那些阶段在时间上密切相关，在这些阶段细胞没有核膜，即桥分隔复合体在前期和前中期之间的过渡阶段形成，并在末期逐渐消失。此外，在某种形式的退化性分裂生殖细胞中，在预先存在的细胞间桥中完全缺乏桥分隔复合体，未被核膜包围的凝聚染色质偶尔会穿过这些开放的桥，因此很可能转移到同一克隆的相邻细胞中。这些结果有力地表明了桥分隔复合体的重要屏障功能。它在有丝分裂缺乏核膜的那些阶段暂时阻止克隆内核物质的交换，从而在同步分裂期间维持雄性生殖细胞的遗传完整性。
