The microtubular cytoskeleton during development of the zygote, proembryo and free-nuclear endosperm inArabidopsis thaliana (L.) Heynh
The microtubular cytoskeleton during development of the zygote, proembryo and free-nuclear endosperm inArabidopsis thaliana (L.) Heynh
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DOI：
10.1007/bf01102418
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发表时间：
1991-05
期刊：
影响因子：
4.3
通讯作者：
M. Webb;B. Gunning
中科院分区：
文献类型：
--
作者：
M. Webb;B. Gunning
在受精卵、原胚和无核胚乳发育过程中，对微管细胞骨架进行了研究。酶分离物中微管蛋白的海藻免疫荧光定位。在整个原胚胎发生过程中，都发现了丰富的微管。合核细胞胚乳中的微管主要分布在内部。相反，在受精卵发育过程中，MTS被重新定位到横向皮质分布，主要是在伴随顶端延伸阶段的亚顶带。这些皮质排列的存在与受精卵的伸长相一致。皮质排列也伴随着圆柱形胚柄的伸长。广泛的MT网络遍布原胚细胞的整个细胞质。在许多类型的细胞中都可以检测到核周排列，在核分裂期间，MT有助于典型的有丝分裂构型。在整个大孢子发生和胚囊发育过程中，MTS的前期带不存在，在胚乳细胞分裂过程中也不出现。我们在受精卵的第一个分裂周期中观察到了MTS。通过将观察到的阶段放在一个最可能的序列中，我们已经确定了这个细胞周期是胚胎发育过程中的一个点，在这个点上，前相带作为细胞分裂的常规特征被恢复。观察到前相带可以预测细胞分裂到八分体阶段的胞质分裂平面。
The microtubular cytoskeleton has been studied during development of the zygote, proembryo and free-nuclear endosperm inA. thalianausing immunofluorescence localization of tubulin in enzymatically isolated material. Abundant micro tubules (MTs) are found throughout proembryogenesis. Microtubules in the coenocytic endosperm are mainly internal. By contrast, there is a re-orientation of MTs to a transverse cortical distribution during zygote development, predominantly in a subapical band which accompanies a phase of apical extension. The presence of these cortical arrays coincides with the elongation of the zygote. Cortical arrays also accompany elongation of the cylindrical suspensor. Extensive networks of MTs ramify throughout the cytoplasm of cells in the proembryo proper. Perinuclear arrays are detected in a number of cell types and MTs contribute to typical mitotic configurations during nuclear divisions. Preprophase bands of MTs are absent throughout megasporogenesis and embryo-sac development and do not occur in endosperm cell divisions. We have observed MTs throughout the first division cycle of the zygote. By placing the observed stages in a most probable sequence, we have identified this cell cycle as the point during embryogenesis at which a preprophase band is reinstated as a regular feature of cell division. Preprophase bands were observed to predict planes of cytokinesis in cell divisions up to the octant stage.