Cortical Cytoskeleton of Euplotes gracilis (Protozoa,Ciliophora) by Non-Ionic Detergent Extraction

By means of non-ionic detergent extraction and scanning electron microscopy,it was shown that the cortical cytoskeleton is a three-dimension network composed of non-ciliaed-regional skeleton,ciliature skeleton and skeleton-associated fibers in Euplotes gracilis.All kinds of the skeleton are made up of the fibers forming fiber net,layer,band,sheet and other structural units.The non-ciliaed cortical skeleton is composed of the surface fiber net and the sub-pellicular fiber layer located in the cortical periphery.The ciliature skeletons,I.e.adoral zone of membranelles skeleton,paroral membrane skeleton and frontal-ventral-transverse cirri skeleton,are located in the cortex according to their corticotype and form an elementary part of the ventral cytoskeleton.Although these skeletons manifested different appearances,they possessed identical structure,namely a functional unit formed by the kinetosomes,ciliature bracket and skeleton-associated fibers.It was supposed that the fiber net forming the regional structures on the cell surface might play a role in connection of the surface parts and in the interaction between the cell and its environment.In ciliature cytoskeleton,the kinetosomal complex might play a role of microtubule-organizing center in the formation of ciliature bracket and skeleton-associated fibers and etc.