摘要
萌发的丝瓜花粉中存在一个动态细胞质纤丝网架,它具有一定的刚性和柔性,是细胞质一流动的基础,制约着细胞质颗粒的运动。电镜照片显示出,网架纤丝主要由许多直径为5-7nm 的微丝相互平行排列而成,并且在两条微丝的相接处具有定向排列的箭头状物。我们认为在微丝上的某些部位可能存在肌球蛋白分子,它们在细胞质纤丝网架变化及细胞质颗粒的运动中起着动力和调节的作用。
In the pollen germinated for more than 4 hours,many cytoplasmic fibrils can be observ- ed under optical microscope.These fibrils which form a network are always in motion,being rigid and flexible to a certain extent,defined as moving cytoplasmic fibril network in the present paper.The network fibrils are different from cytoplasmic streaming,because they not only move vertically but also horizontally.Furthermore,they restrict the transportation of cytoplasmic particles.Electron micrographs show that the fibrils are composed of many par- allel microfilaments with 5—7 nm in diameter,and at the joint of two microfilaments there are arrowheaded compounds in the same direction and the same distance about 420.They may be the force“motor”and the“viscous cluch”formed by the directional arrangement of myo- sin which is necessary to the movement of both fibrils and cytoplasmic particles.
关键词
萌发花粉
胞质纤丝网架
胞质颗粒
Germinated pollen
Cytoplasmic fibril network
The movement of cytoplasmic particles
