Ultrastructure of somatic muscle cells in Ascaris lumbricoides. II. Intermuscular junctions, neuromuscular junctions, and glycogen stores.
Ultrastructure of somatic muscle cells in Ascaris lumbricoides. II. Intermuscular junctions, neuromuscular junctions, and glycogen stores.
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DOI：
10.1083/jcb.26.2.579
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发表时间：
1965-08
期刊：
影响因子：
--
通讯作者：
Rosenbluth J
中科院分区：
文献类型：
--
作者：
Rosenbluth J
蛔虫的体肌细胞由三种不同的特化成分组成，称为纤维，其中包含收缩装置（如前所述），腹部和手臂。腹部是一个糖原囊，在动物饥饿期间耗尽。手臂延伸到神经索，在那里它建立了一个肌神经接头，其特征在于神经纤维中的巨大线粒体和囊泡簇以及500 A的神经肌肉间隙。这些臂在神经索附近被证明是“电互连的”，仅在这个区域彼此形成“紧密连接”。在高放大率下，这些连接可以分为几种类型。在某些情况下，膜的外小叶融合，形成中间线。其他类似分隔桥粒的是，在膜之间保留有宽度为20埃的残余细胞外空间，但外部小叶跨越差距相互连接。建议术语“紧密连接”包括仅在高放大率下可区分的各种结构，并且不同的变化不一定在功能上等同。
Somatic muscle cells of Ascaris lumbricoides consist of three differently specialized components referred to as the fiber, which contains the contractile apparatus (described previously), the belly, and the arm. The belly is shown to be a sac of glycogen, which is depleted during starvation of the animal. The arm extends to a nerve cord where it establishes a myoneural junction characterized by giant mitochondria and clusters of vesicles in the nerve fibers and by a 500 A neuromuscular gap. The arms, which have been shown to be "electrically interconnected" in the vicinity of the nerve cord, form "tight junctions" with one another in just this region. At high magnification, these junctions can be resolved into several types. In some there is fusion of the outer leaflets of the membranes with formation of an intermediate line. Others resemble septate desmosomes in that a residual extracellular space ∼20 A in width remains between the membranes, but the outer leaflets are interconnected across the gap. It is suggested that the term "tight junction" encompasses a variety of structures distinguishable only at high magnification and that the different variations are not necessarily equivalent functionally.