Studies on Electrofusim of Plant Protoplasts Using High Speed Microscopy

肌动蛋白是植物细胞骨架的重要组成部分，不仅参与细胞的构筑，而且还参与细胞的运动。细胞融合是研究细胞发育和随后的细胞分裂的重要过程。本文报道了电融合早期原生质体的三维结构和动态变化。1)记录时间分辨现象的新技术已经开发出使用条纹相机和偏光显微镜。结果表明，该技术在肌肉收缩和细胞融合的研究中具有重要的应用价值。2)通过对时间分辨双折射的分析，我们获得了收缩肌原纤维的亚微秒和微秒旋转运动。3)我们分析了施加交流电场和直流脉冲后肌动蛋白丝的位置和运动。4)我们观察到成束的肌动蛋白丝形成了电缆和网络。5）用高压电子显微镜（1MeV）对原生质体进行了三维观察，得到了一对体视显微照片。融合细胞间的接触处出现环状肌动蛋白丝结构。我们发现了连接肌动蛋白丝之间的关节颗粒。6)在UVSOR装置上安装了带波带片的软X射线显微镜，拍摄了干、湿原生质体的X射线显微照片。原生质体的X射线显微照片与光学和电子显微照片进行了比较。

Actin is an important component of plant cytoskeleton that not only involved in contributing to the cytoarchitecture of cells but also in cell motility. Cell fusion is an important process for studying the development of the cell and for the subsequent cell division. The study is to report on three dimensional structures and dynamic aspects of plant protoplasts during early process of electrofusion. 1) New technology for recording the time-resolved phenomena has developed using a streak camera and a polarization microscope. We obtained that the technique is very useful in the study of muscle contraction and cell fusion. 2) We obtained sub microsecond and microsecond rotational motions with in the contractile myofibrils by analyzing the time-resolved birefringence. 3) We analyzed the location and movement of actin filaments after the application with AC field and DC pulse. 4) We observed that bundles of actin filaments are forming cables and networks 5) Three dimensional observations of protoplasts were also made by a high voltage electron microscope (1 MeV) equipped a revolving stage to get a pair of stereo-micrographs. Ring structure of actin filaments appeared at the contact areas between fused cells. We found the joint particle connecting between actin filaments. 6) A soft X-ray microscope with zone plate was installed at UVSOR.The X-ray micrographs of dry and wet protophasts were taken. X-ray micrographs of protoplasts were compared with those of optical and electron micrographs.