绿色杜氏藻被膜泡囊的超微结构研究

ULTRASTRUCTURAL STUDY OF COATED VESICLES IN DUNALIELLA VIRIDIS TEOD

于1990年5月—1991年5月，运用透射电镜观察绿色杜氏藻，对该藻被膜泡囊的形态结构及其在细胞内的分布和形成过程进行研究。观察表明，绿色杜氏藻细胞的高尔基体和细胞膜附近有许多大小不等的被膜泡囊；这些被膜泡囊由泡囊及其表面的网状结构构成，其直径在45—120nm之间；在细胞膜附近的被膜泡囊直径较大；在高尔基体和细胞膜上还观察到被膜泡囊的形成过程。结果提示：在处于指数生长期的绿色杜氏藻细胞中，被膜泡囊起着细胞内大分子物质运输的作用。

Ultrastructural study was conducted on coated vesicles, their djstribuhon and formationin Dunaliella viridis Teod in the algal physiology laboratory of the Inshtute of Oceanology fromMay 1990 to May 1991. Cells were cultivated under the light of 5000lx(12h: 12h) and at thetemperature of 21 ±1℃ until an exponential growth phase was reached. They were collected andfixed with 3% glutaraldehyde and 1% OsO4 in 0.2mol / L phosphate buffer (pH = 7.4), dehychatedthrough ethanol series and embedded in Epon resin afterwed. Sample sechons were postStained withurany acetate and lead citrate and observed in a Hitachi 500 transmission electron microscope at80kV. The result shows that coated vesicles were spherical and covered with electron dense granules.They were present in large numbers and closely associated with golgi cistemae and dictyosome (PlateI:1-2). Their sizes ranged between 45-72nm in diameter. Some coated vesicles were budding fromor laying near these structures. The similar electron dence grmules at the end of the cisternalmargins strongly suggest an intrinsic relation between Golgi apparatus and coated vesicles. At thevicinity of plasma membrance, coated vesicles were also observed. They were larger than thoseassociated with Golgi apparetus and their sizes were 65-120nm in diameter. On the plasmamembrane, parts of the membrane invaginated towards the inside of the cell and formed coated pits(Plate I:3). These Pits were also surrounded by electron dense granules at the cytosolic side of themembrane (Plate 1：4). With the deepening of the invagination, the coated Pits were ghouallydessociated with Plasma membran and electron dense grmules completely covered the surfase of themembare vesicles. In this way, a coated vesicle was formed into the cytoplasm (Plate I: 5).Preliminary results indicate that the coated vesicles may Play a role in intuellular traffic of macromolecules and exchange of material across the plasma membrane in these cells.