Rebuilding MTOCs upon centriole loss during mouse oogenesis
Rebuilding MTOCs upon centriole loss during mouse oogenesis
复制标题
DOI：
10.1016/j.ydbio.2013.07.029
复制
发表时间：
2013-10-01
影响因子：
2.7
通讯作者：
Brunet, Stephane
中科院分区：
文献类型：
--
作者：
Luksza, Malgorzata;Queguigner, Isabelle;Brunet, Stephane
绝大多数动物细胞含有典型的中心体作为主要的微管组织中心，由一对中心粒定义。脊椎动物的卵母细胞在卵子发生的早期阶段就开始释放中心粒，这是一个罕见的例外。在卵子发生末期，中心体最终被许多无中心微管组织中心（MTOC）所取代，这些中心在减数分裂期间形成纺锤体极。卵母细胞中中心体和无中心粒MTOC的代谢机制尚未阐明。此外，在卵母细胞生长阶段中心体解体后，对微管组织及其对细胞内结构的影响知之甚少。我们已经研究了这个问题，在小鼠中耦合免疫荧光和实时成像的方法。我们表明，生长中的卵母细胞含有分散的中心周围物质，负责整个细胞中的微管组装和分布。PCM灶的逐渐扩大最终导致在有能力的卵母细胞中形成大的核周MTOC和从核附近发出的大微管星状体的组装。减数分裂恢复后，核周MTOC围绕核膜扩散，核膜在分裂前通过MT和动力蛋白依赖性机制平行重塑。只有完全有能力的卵母细胞才能在NEBD进行这种戏剧性的重组。因此，我们描述的MTOC-MT重组是小鼠卵母细胞能力的关键特征之一。(C)2013 Elsevier Inc. All rights reserved.
The vast majority of animal cells contain canonical centrosomes as a main microtubule-organizing center defined by a central pair of centrioles. As a rare and striking exception to this rule, vertebrate oocytes loose their centrioles at an early step of oogenesis. At the end of oogenesis, centrosomes are eventually replaced by numerous acentriolar microtubule-organizing centers (MTOCs) that shape the spindle poles during meiotic divisions. The mechanisms involved in centrosome and acentriolar MTOCs metabolism in oocytes have not been elucidated yet. In addition, little is known about microtubule organization and its impact on intracellular architecture during the oocyte growth phase following centrosome disassembly. We have investigated this question in the mouse by coupling immunofluorescence and live-imaging approaches. We show that growing oocytes contain dispersed pericentriolar material, responsible for microtubule assembly and distribution all over the cell. The gradual enlargement of PCM foci eventually leads in competent oocytes to the formation of big perinuclear MTOCs and to the assembly of large microtubule asters emanating from the close vicinity of the nucleus. Upon meiosis resumption, perinuclear MTOCs spread around the nuclear envelope, which in parallel is remodelled before breaking-down, via a MT- and dynein-dependent mechanism. Only fully competent oocytes are able to perform this dramatic reorganization at NEBD. Therefore, the MTOC-MT reorganization that we describe is one of key feature of mouse oocyte competency. (C) 2013 Elsevier Inc. All rights reserved.