Studies On The Cortex And Microtubular Cytoskeleton In Marine Euplotes Sp.

Euplotes is one special species on the differentiation of the cortex and nucleus in Hypotrichous ciliates, protozoan. Cell ciliatures include front-ventral cirri, transverse cirri, caudal cirri and dorsal kineties, etc. There are one macronucleus and one globose micronucleus in cell. Moreover, the cell has the complex microtubular organelles which display the typical characteristics of the single-celled eucaryote At present the scientists in many fields are focus on Euplotes. With the development of life sciences and experimental techniques the studies have focused on the fields of molecular and ultrastructure about the cell modality, morphogenesis and physiological functions. But the conclusions mainly come from freshwater Euplotes. The information from the marine Euplotes is lacking. Therefore, we studied one marine Euplotes sp. in cell morphology and membrane proteins and compared it with one freshwater Euplotes sp..(1) Ultrastructure of cell surface, cortex and cytoplasm By means of scanning electron microscopy and transmission electron microscopy, it was shown that the features of cell surface, cortex and cytoplasm. This species is different from other species of freshwater Euplotes which have been reported. It has 10 frontal-ventral cirri, 5 transverse cirri, and 5 caudal cirri; 8-9 dorsal kineties, etc. There was rod-shaped structure in pellicle which the function must continue to be considered. Contractile vacuole pore had not been observed but there was one small pore under the right frontal-ventral cirrum. It is supposedly that the pore can regulate the osmotic pressure of the cell. Cilia are composedof nine triplet microtubules and two central microtubules. Fibrillar cirral basket is around the basal bodies. Nuclei, mitochondrion and cortical ampule are in cytoplasm. It is supposedly that cortical ampule are related to the regulation of the osmotic pressure. The observations about the ultratructure, silverline system and arrangement of microtubules will come under research.(2) Observation on morphogenesis of microtubule organelles and cortical cytoskeletonthis research used FLUTAX and α -tubulin antibody as the probes to mark growing progress of microtubule organelles in mitosis and observe the cortical microtubule cytoskeleton in non-mitosis. During the asexual reproduction the newly cilia are nearly related with the primary cilia. In non-mitosis comparing with the freshwater Euplotes sp., the marine Euplotes sp .has less developed frontal-ventral cirri cytoskeleton, more radiating fibers in venter and more transverse microtubule bundles in dorsal side. On the contrary the freshwater Euplotes sp. has more developed frontal-ventral cirri cytoskeleton and more lengthways microtubule bundles in dorsal side These results supply the complementarities of the components of cortical cytoskeleton in Euplotes.(3) Analysis on components of cell membrane proteinsThe marine Euplotes sp. exist in seawater where is the especial environment. Therefore this research related to the comparison of integral membrane proteins between two euplotes. Integral membrane proteins are characterized by a hydrophobic domain which interacts directly with the hydrophobic core of the lipid bilayer. Nonionic detergents are widely used for the solubilization of these proteins. By means of the nonionic detergent phase separation and gel electrophoresis, it was shown that bands corresponding to 123,77.5 and 52kD were present in two euplots, but had different contents. The marine Euplotes sp. had the bands corresponding to 102, 63 and 43kD and the freshwater Euplotes sp. had the bands corresponding to 99.5, 29 and 27kD. Maybe these differences related to the living environment.