New insights on Laminaria digitata ultrastructure through combined conventional chemical fixation and cryofixation
New insights on Laminaria digitata ultrastructure through combined conventional chemical fixation and cryofixation
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DOI：
10.1515/bot-2021-0005
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发表时间：
2021-01-01
期刊：
影响因子：
2.2
通讯作者：
Kuepper, Frithjof Christian
中科院分区：
文献类型：
--
作者：
Katsaros, Christos;Le Panse, Sophie;Kuepper, Frithjof Christian
本研究的目的是研究化学固定和冷冻固定对海带营养细胞精细结构的影响。之所以选择海带藻，是因为它在广泛的生物学研究中是一种重要的模式生物，是北大西洋岩石海岸的关键物种，它使用碘化物作为一种独特的无机抗氧化剂，并且它作为生产海藻酸盐的原料具有重要意义。详细描述了营养细胞的精细结构特征，特别强调了所使用的两种方法之间的差异，即传统的化学固定和冷冻固定。细胞的总体结构与前面描述的相似，不同细胞类型之间存在细微差异。高尔基体系统的强烈活动被发现与厚的外细胞壁有关，大的双胞体从中释放出许多囊泡和池。在冷冻材料中发现了一种有趣的池，这种池在化学固定中是不可见的。它们是细长的结构，部分呈小管状，靠近外细胞壁或幼细胞壁。在坑田的胞间连丝附近观察到这些结构的数量增加。它们类似于与形成褐藻细胞动力学隔膜有关的“扁平池”。讨论了它们可能的作用。这项工作的新发现强调了这种联合研究的重要性，这些研究揭示了直到现在使用旧的传统方法还不知道的新数据。本研究的主要结论是冷冻固定是透射电镜研究海带细胞学的首选方法。
The objective of the present study is to examine the fine structure of vegetative cells of Laminaria digitata using both chemical fixation and cryofixation. Laminaria digitata was chosen due to its importance as a model organism in a wide range of biological studies, as a keystone species on rocky shores of the North Atlantic, its use of iodide as a unique inorganic antioxidant, and its significance as a raw material for the production of alginate. Details of the fine structural features of vegetative cells are described, with particular emphasis on the differences between the two methods used, i.e. conventional chemical fixation and freeze-fixation. The general structure of the cells was similar to that already described, with minor differences between the different cell types. An intense activity of the Golgi system was found associated with the thick external cell wall, with large dictyosomes from which numerous vesicles and cisternae are released. An interesting type of cisternae was found in the cryofixed material, which was not visible with the chemical fixation. These are elongated structures, in sections appearing tubule-like, close to the external cell wall or to young internal walls. An increased number of these structures was observed near the plasmodesmata of the pit fields. They are similar to the "flat cisternae" found associated with the forming cytokinetic diaphragm of brown algae. Their possible role is discussed. The new findings of this work underline the importance of such combined studies which reveal new data not known until now using the old conventional methods. The main conclusion of the present study is that cryofixation is the method of choice for studying Laminaria cytology by transmission electron microscopy.