Microtubule patterning during meiotic maturation in mouse oocytes is determined by cell cycle-specific sorting and redistribution of γ-tubulin
Microtubule patterning during meiotic maturation in mouse oocytes is determined by cell cycle-specific sorting and redistribution of γ-tubulin
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DOI：
10.1006/dbio.2001.0444
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发表时间：
2001-11-15
影响因子：
2.7
通讯作者：
Albertini, DF
中科院分区：
文献类型：
--
作者：
Combelles, CMH;Albertini, DF
动物卵母细胞减数分裂成熟过程中微管组装事件的拓扑结构需要严格的空间控制和时间精度。为了更好地理解是什么调节微管组装的时间和位置，在减数分裂进展的特定阶段评价了同步成熟的小鼠卵母细胞的γ-微管蛋白、中心周围蛋白和总微管蛋白聚合物级分。γ-微管蛋白通过减数分裂终变期与细胞质中心体结合。在染色质凝聚和核周中心体聚集后，γ-微管蛋白重新定位到核板层结合的隔室中，其中发生减数分裂-1纺锤体组装。γ-微管蛋白从前中期-1到后期-2稳定地与减数分裂纺锤体结合，但也表现出细胞周期特异性的重定位到细胞质中心体。具体地说，减数分裂后期开始-1和-2的特点是伴随出现的γ-微管蛋白和微管成核在皮层下中心体。在特定细胞周期阶段应用紫杉醇的短暂脉冲增强了γ-微管蛋白区室化的检测，这与减数分裂进程中微管组装的γ-微管蛋白定位依赖性空间限制一致。此外，在减数分裂恢复期间的紫杉醇脉冲损害了随后的γ-微管蛋白分选，导致单极纺锤体形成和减数分裂-1中的细胞周期停滞;尽管细胞周期停滞，但极体挤出大致按计划发生。因此，γ-微管蛋白的分选参与小鼠卵母细胞中减数分裂纺锤体组装的定位时机以及有丝分裂和胞质分裂的协调。(C)北京：科学出版社.
The topography of microtubule assembly events during meiotic maturation of animal oocytes demands tight spatial control and temporal precision. To better understand what regulates the timing and location of microtubule assembly, synchronously maturing mouse oocytes were evaluated with respect to gamma -tubulin, pericentrin, and total tubulin polymer fractions at specific stages of meiotic progression. gamma -Tubulin remained associated with cytoplasmic centrosomes through diakinesis of meiosis-1. Following chromatin condensation and perinuclear centrosome aggregation, gamma -tubulin relocated to a nuclear lamina-bounded compartment in which meiosis-1 spindle assembly occurred. gamma -Tubulin was stably associated with the meiotic spindle from prometaphase-1 through to anaphase-2, but also exhibited cell cycle-specific relocalization to cytoplasmic centrosomes. Specifically, anaphase onset of both meiosis-1 and -2 was characterized by the concomitant appearance of gamma -tubulin and microtubule nucleation in subcortical centrosomes. Brief pulses of taxol applied at specific cell cycle stages enhanced detection of gamma -tubulin compartmentalization, consistent with a gamma -tubulin localization-dependent spatial restriction of microtubule assembly during meiotic progression. In addition, a taxol pulse during meiotic resumption impaired subsequent gamma -tubulin sorting, resulting in monopolar spindle formation and cell cycle arrest in meiosis-1; despite cell cycle arrest, polar body extrusion occurred roughly on schedule. Therefore, sorting of gamma -tubulin is involved in both the timing of location of meiotic spindle assembly as well as the coordination of karyokinesis and cytokinesis in mouse oocytes. (C) 2001 Academic Press.