Ultrastructure of the membranous layers enveloping the cell of the coccolithophoridEmiliania huxleyi

Journal of ultrastructure research Pub Date : 1985-04-01 DOI:10.1016/0889-1605(85)90072-2

P. van der Wal , J.J.M. Leunissen-Bijvelt , A.J. Verkleij

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引用次数: 11

Abstract

Emiliania huxleyi is a marine unicellular alga that is covered by one or several layers of coccoliths (discs of crystalline calcium carbonate) or of organic scales. Immediately proximal to these layers are several membranous layers that surround the protoplast. In this study an ultrastructural analysis of this membranous envelope is presented using ultrathin-section and freeze-fracture electron microscopy. We found that the protoplast ofE. huxleyi is surrounded in a proximal-to-distal direction by a membrane studded with intramembranous particles (IMPs), an intermediate structure consisting of several smooth layers, and an outermost membrane studded with IMPs. On freeze-fracturing the intermediate structure reveals two or three closely apposed smooth fracture faces. It is possible that this structure consists of two or three membranes that are devoid of IMPs. However, the possibility is also discussed that this structure is composed of three or four lipid monolayers so closely stacked that water is hardly or not present between them.

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胡氏艾美耳球虫细胞膜层的超微结构

huxleyi Emiliania是一种海洋单细胞藻类，被一层或多层尾石（结晶碳酸钙盘）或有机鳞片覆盖。紧邻这些层的是围绕原生质体的几个膜层。在本研究中，用超薄切片和冷冻断裂电子显微镜对这种膜包膜进行了超微结构分析。我们发现E。huxleyi在近端到远端的方向上被镶嵌有膜内颗粒（IMP）的膜、由几个光滑层组成的中间结构和镶嵌有IMP的最外层膜包围。冻结压裂时，中间结构显示出两个或三个紧密排列的光滑断裂面。这种结构可能由两个或三个没有IMP的膜组成。然而，也讨论了这种结构由三到四个紧密堆叠的脂质单层组成的可能性，使得它们之间几乎不存在或不存在水。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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Journal of ultrastructure research

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