Studies On Ultrastructures Of Intermediate-type Filament Systems And Some Submicroscopic Structures In Two Ciliates

This paper is concerned with the microscopic structure and function of protozoan cortex intermediate-type filament systems. Based on the theory of erythrocyte spectrin technology, using KMnO4 as fixative in scanning electron microscopy(SEM) experiments and adjust the concentration of it, then get the broken cell membrane samples. Observed the intermediate-type filament systems and Some submicroscopic structures of hypotrichous ciliate pseudourostyla cristata and Stylonychia lemnae under the scanning electron microscope. The followings are the results of the study:1. The cortex intermediate-type filament systemsBoth ciliates were observed by 10 nm diameter of single fiber and 10~30nm diameter of reticular fiber Under the cell membrane. The position of filament under the cell membrane is: cell membrane, cortical granules and the intermediate-type filament. there is no obvious double membrane structure in pseudourostyla cristata, the cell surface membrane was more thinner and the cortex intermediate-type filament was more thicker and compact than the other ciliate. It can be concluded that intermediate-type filament structure can play the role of cytoskeleton and maintain cell morphology. The morphology and distribution density of Intermediate-type filament structure should be different in different ciliates2. The combined distribution of intermediate-type filament structures and other organelles in the cellInside the cell from cortex also found a large number of intermediate-type filament structures. The sparse network area is a kind of intermediate fibers with diameter of 10 nm, and the dense network area is mainly a kind of intermediate fiber or fiber bundle with 10~30nm diameter. Some of these intermediate fibers are connected to cortical granules, Fiber Network of food, macronucleus and so on. The intermediate-type filaments in the two ciliate are different, compact intermediate-type filament wrapped food vacuoles, sparse coarse fiber structure winding at the periphery was found in Stylonychia lemnae. It can not only maintain organelle morphology and maintained the variety of cell structure, but also contact various organelles between each other.3. The relationship between nucleus and intermediate-type filamentsThe morphology of macronucleus and the distribution of nuclear pore was both observed In two species of ciliates. Two forms of macronucleus cells was observed in Urostyla cristata, one forms of macronucleus cells was observed in Stylonychia lemnae. Intermediate-type filament wrapped with nucleus and connected it with other cytoplasm and cytoplasmic vesicular structures. It can conclude that this structure may transfer nuclear signal inside and outside the cells, cell communication and establish a foundation with each other.4. Cytopharynx observation about Stylonychia lemnaeThe funnel-shaped cytopharynx was observed under the sample of broken cell membrane. It is a new experimental method to observe the Stylonychia lemnae pharyngeal three-dimensional conformation, and also the first one to show the hypotrichous ciliate’s three-dimensional structure of cytopharynx. A layer of intermediate-type filaments interwoven densely to form a funnel-basket shaped structure covering the cytopharynx, with cytopharynx extends into the cell, a membrane-type structure covered the basket-type structure. It showed that the intermediate-type structure was highly correlated with the function of digestion and feeding.5. Cortex surface extrusome about Stylonychia lemnae.Extrusome structure had found near the ventral Adoral zone and both sides of the back. This structure is spherical, with a diameter of 0.5~1.5μm. It can be assumed that these spheres should be cortical granules in Stylonychia lemnae. Because of the improvement of the fixing liquid, the cortical granule is released from the cell to the cell surface.