Studies on the motility of the foraminifera. I. Ultrastructure of the reticulopodial network of Allogromia laticollaris (Arnold).
Studies on the motility of the foraminifera. I. Ultrastructure of the reticulopodial network of Allogromia laticollaris (Arnold).
复制标题
关于有孔虫运动的研究。 I.同种异体Laticollaris（Arnold）的网状网络的超微结构。
DOI：
10.1083/jcb.90.1.211
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发表时间：
1981-07
影响因子：
7.8
通讯作者：
Allen, R D
中科院分区：
文献类型：
--
作者：
Travis, J L;Allen, R D
宽腹异形虫是一种底栖海洋有孔虫，它延伸出大量的主干丝状足孔，这些主干足孔反复分支、吻合和再次融合形成网状足孔网络(RPN)，在该网络中细胞质颗粒不断流动。颗粒的运动是跳跃的和双向的，即使在光学显微镜检测到的最薄的丝状足孔中也是如此。差示干涉显微镜下可以看到纤丝，在偏振光中，PRN呈现正的双折射。在稳定微管(MT)的溶液中裂解和提取RPN后，这些原纤维保持完好。通过这些裂解和稳定的细胞骨架模型的薄片的电子显微镜显示出MTS的束状结构。活体异体骨的RPN只有在适应无钙海水后，才能用标准EM固定剂保存，无钙海水流动正常。RPN中的MT通常排列成束状，通常平行于主干和分支丝状伪足的长轴。整体安装、固定和临界点干燥生物的立体电子显微镜显示，MT部署的复杂模式反映了RPN的扁平和高度分枝部分的粒子运动模式。细胞质颗粒，其中一些具有模糊的被毛，与单一的MTS或MT束密切相关，并优先定向。细丝(约5 nm)也在网状结构内观察到，与MTS平行或交错排列，并位于丝状伪足的扁平末端区域。在对照组(人类血小板)肌动蛋白细丝大量装饰的条件下，这些细丝不能结合骨骼肌肌球蛋白S1，并且大约20%太薄，无法在超微结构上被鉴定为F-肌动蛋白。
Allogromia laticollaris, a benthic marine foraminifer, extends numerous trunk filopodia that repeatedly branch, anastomose, and fuse again to form the reticulopodial network (RPN), within which an incessant streaming of cytoplasmic particles occurs. The motion of the particles is saltatory and bidirectional, even in the thinnest filopodia detected by optical microscopy. Fibrils are visible by differential interference microscopy, and the PRN displays positive birefringence in polarized light. These fibrils remain intact after lysis and extraction of the RPN in solutions that stabilize microtubules (MTs). Electron micrographs of thin sections through these lysed and stabilized cytoskeletal models reveal bundles of MTs. The RPNs of living Allogromia may be preserved by standard EM fixatives only after acclimatization to calcium-free seawater, in which the streaming is normal. The MTs in the RPN are typically arranged in bundles that generally lie parallel to the long axis of the trunk and branch filopodia. Stereo electron micrographs of whole-mount, fixed, and critical-point-dried organisms show that the complex pattern of MT deployment reflects the pattern of particle motion in both flattened and highly branched portions of the RPN. Cytoplasmic particles, some of which have a fuzzy coat, are closely associated with, and preferentially oriented along, either single MTs or MT bundles. Thin filaments (approximately 5 nm) are also observed within the network, lying parallel to and interdigitating with the MTs, and in flattened terminal areas of the filopodia. These filaments do not bind skeletal muscle myosin S1 under conditions that heavily decorate actin filaments in controls (human blood platelets), and are approximately 20% too thin to be identified ultrastructurally as F-actin.