PROTOPLASMIC MOVEMENT IN THE FORAMINIFERAN, ALLOGROMIA-LATICOLLARIS - AND A THEORY OF ITS MECHANISM
PROTOPLASMIC MOVEMENT IN THE FORAMINIFERAN, ALLOGROMIA-LATICOLLARIS - AND A THEORY OF ITS MECHANISM
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DOI：
10.2307/1539042
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发表时间：
1959-01-01
影响因子：
1.6
通讯作者：
RINALDI, RA
中科院分区：
文献类型：
--
作者：
JAHN, TL;RINALDI, RA
侧颈异色瓢虫网状足中的原生质流动是由两条在伪足末端相互连续的浆凝胶线组成的双向运动，它们与附着的颗粒共同构成了较小网状足的整个结构。没有凝胶管，没有硬质的中心核，也没有外部透明层。这似乎是已知存在的最简单的细丝流形式。有人提出，长丝流动的机制包括主动剪切力位于相邻表面之间的2凝胶长丝纵向和相反的作用，从一个长丝到另一个，以产生双向流动。这一理论将解释在没有凝胶管和一个中央核心的硬质，在每个伪足的尖端移动颗粒的方向的逆转，在较大的伪足中存在许多平行但独立的通路，在新切伪足中存在双向流，以及在小原生质碎片中存在正常流的情况下的运动。有人建议，网状足的凝胶线程可能不会被一个典型的细胞膜，但膜可能只是表面的凝胶丝本身。主动剪切力理论在其他材料中的原生质运动的可能应用和可能存在的2种主要类型的原生质运动，即压力流和细丝流的分类学意义进行了讨论。
Protoplasmic streaming in the reticulopodia of Allogromia laticollaris is always a 2-directional movement of 2 threads of plasmagel, continuous with each other at the end of the pseudopodium, which, together with the attached granules, make up the entire structure of the smaller reticulopodia. There is no gel tube, no central core of stereoplasm, and no outer hyaline layer. This seems to be the simplest form of filament streaming known to exist. It is proposed that the mechanism of filament streaming consists of active shearing forces located between the adjacent surfaces of the 2 gel filaments acting longitudinally and oppositely from one filament to the other so as to produce 2-way streaming. This theory will explain movement in the absence of a gel tube and of a central core of stereoplasm, the reversal of direction of moving granules at the tip of each pseudopodium, the presence of numerous parallel but separate pathways in the larger pseudopodia, the presence of 2-way streaming in freshly cut pseudopodia, and the presence of normal streaming in small protoplasmic fragments. It is suggested that the gel threads of the reticulopodia may not be covered by a typical cell membrane but that the membrane may be merely the surface of the gel filament itself. Possible applications of the theory of active shearing forces to protoplasmic movement in other materials and the possible taxonomic significance of the existence of 2 major types of protoplasmic movements, namely pressure flow and filament streaming, are discussed.