Electron tomographic analysis of cytokinesis in the brown alga Silvetia babingtonii (Fucales, Phaeophyceae)
Electron tomographic analysis of cytokinesis in the brown alga Silvetia babingtonii (Fucales, Phaeophyceae)
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褐藻 Silvetia babingtonii（墨角藻目，褐藻纲）胞质分裂的电子断层扫描分析
DOI：
10.1007/s00709-014-0635-y
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发表时间：
2014
期刊：
影响因子：
2.9
通讯作者：
Taizo Motomura
中科院分区：
文献类型：
--
作者：
Chikako Nagasato;Naoko Kajimura;Makoto Terauchi;Yoshinobu Mineyuki;Taizo Motomura
在褐藻中，胞质分裂过程中新细胞分配的膜资源主要是扁平池（FCs）和高尔基体衍生的小泡。我们使用电子断层扫描结合快速冷冻/冷冻置换合子，以澄清瞬时膜室的结构在胞质分裂inSilvetiazygotes。有丝分裂后，一个无定形的膜结构，被认为是一个FC中间体观察附近的内质网簇，位于两个子核之间。FC在细胞运动平面上排列，周围形成管状膜状网络。这种网络可能是由连接到FC边缘的球形囊泡连续融合形成的，以形成膜网络（MN）。在从MN形成膜囊（MS）的初始阶段，MS具有平坦和肿胀的部分，后者显示膜隧道。在MS的肿胀部分检测到高频率的包被凹坑。这一观察结果表明，通过内吞作用回收多余的膜，膜隧道消失，肿胀部分变得平坦。MN出现在生长的MS的边缘，MN和MN-MS复合物沿细胞动力学平面在几个空间观察到沿着。MS通过并入MN或其邻近的其它MS而扩展。随着新细胞间隔膜的成熟，MS的厚度趋于恒定，膜腔消失。从断层扫描数据分析胞质分裂过程中瞬时膜室的表面积和体积的变化。
In brown algae, membrane resources for the new cell partition during cytokinesis are mainly flat cisternae (FCs) and Golgi-derived vesicles. We used electron tomography coupled with rapid freezing/freeze substitution of zygotes to clarify the structure of transient membrane compartments during cytokinesis inSilvetiazygotes. After mitosis, an amorphous membranous structure, considered to be an FC intermediate was observed near endoplasmic reticulum clusters, lying between two daughter nuclei. FCs were arrayed at the cytokinetic plane, and a tubular membranous network was formed around them. This network might be formed by the consecutive fusion of spherical vesicles that are linked to the edges of FCs to form a membranous network (MN). At the initial stage of the formation of a membranous sac (MS) from the MN, the MS had flat and swollen parts, with the latter showing membranous tunnels. Coated pits were detected with high frequency at the swollen parts of the MS. This observation indicated that membranous tunnels disappeared by recycling of excess membrane via endocytosis, and the swollen part became flat. The MN appeared at the edges of the growing MS. MN and the MN-MS complex were observed along the cytokinetic plane in several spaces. The MS expanded by the incorporation of MN or other MS in its neighborhood. With the maturation of the new cell partition membrane, the thickness of the MS became constant and the membrane cavity disappeared. The changes in the surface area and volume of the transient membrane compartment during cytokinesis were analyzed from the tomographic data.