Organization and regulation of cortical microtubules during the first cell cycle of Xenopus eggs.
Organization and regulation of cortical microtubules during the first cell cycle of Xenopus eggs.
复制标题
DOI：
--
复制
发表时间：
1992-03
期刊：
影响因子：
4.6
通讯作者：
M. Schroeder;David L. Gard
中科院分区：
文献类型：
--
作者：
M. Schroeder;David L. Gard
抗微管蛋白抗体和共聚焦免疫荧光显微镜检查的组织和调节的细胞质和皮质微管在第一个细胞周期的受精非洲爪蟾卵。卵皮质中微管的出现与精子星的生长时间一致。精子的微管在0.25时首先到达动物皮层，（以第一次卵裂为标准的时间），形成径向组织的皮层微管阵列。早在0.35时，植物皮层中就出现了微管的无序网络。动物和植物大脑半球的皮质微管网络重组的时间对应于负责规格的背腹（D-V）轴的皮质旋转。光学切片表明，在受精卵中，皮层微管与精子的微管是连续的，或者在激活的卵中，皮层微管与广泛的激活的微管是连续的。在有丝分裂过程中，皮质微管的组装和组织以及拆卸都与MPF激活不一致。然而，环己酰亚胺或6-二甲基氨基嘌呤可以在间期阻止受精卵，从而阻止皮质微管的分解。注射p13，一种特异性抑制MPF激活的蛋白质，延迟或抑制皮质微管的分解。相比之下，注射cyc delta 90（一种截短的细胞周期蛋白，可将卵子阻滞在M期）的卵子显示出正常的微管分解。最后，注射部分纯化的MPF到环己酰亚胺逮捕的鸡蛋诱导皮质微管断裂。这些结果表明，尽管缺乏时间上的巧合，皮质微管的崩溃是依赖于MPF的激活。
Anti-tubulin antibodies and confocal immunofluorescence microscopy were used to examine the organization and regulation of cytoplasmic and cortical microtubules during the first cell cycle of fertilized Xenopus eggs. Appearance of microtubules in the egg cortex temporally coincided with the outgrowth of the sperm aster. Microtubules of the sperm aster first reached the animal cortex at 0.25, (times normalized to first cleavage), forming a radially organized array of cortical microtubules. A disordered network of microtubules was apparent in the vegetal cortex as early as 0.35. Cortical microtubule networks of both animal and vegetal hemispheres were reorganized at times corresponding to the cortical rotation responsible for specification of the dorsal-ventral (D-V) axis. Optical sections suggest that the cortical microtubules are continuous with the microtubules of the sperm aster in fertilized eggs, or an extensive activation aster in activated eggs. Neither assembly and organization, nor disassembly of the cortical microtubules coincided with MPF activation during mitosis. However, cycloheximide or 6-dimethylaminopurine, which arrest fertilized eggs at interphase, blocked cortical microtubule disassembly. Injection of p13, a protein that specifically inhibits MPF activation, delayed or inhibited cortical microtubule breakdown. In contrast, eggs injected with cyc delta 90, a truncated cyclin that arrest eggs in M-phase, showed normal microtubule disassembly. Finally, injection of partially purified MPF into cycloheximide-arrested eggs induced cortical microtubule breakdown. These results suggest that, despite a lack of temporal coincidence, breakdown of the cortical microtubules is dependent on the activation of MPF.