Observations On The Micro-and Ultra-Structure Of The Cortical Microtubule Cytoskeleton And Cytoplasmic Organelles Of Soil Ciliate Pattersoniella Vitiphila(Hypotrichida,Ciliophora)

Hypotrichous ciliates contain complex microtubule cytoskeleton,including cilia affiliated microtubules and non-cilia affiliated microtubules.Microtubule cytoskeleton is important to cell movement,morphology stabilityand cell division.The hypotrichous ciliates have a great diversity of species.The characteristics of microtubule cytoskeleton in this ciliate group show both similarities and specificities among species.Related information has been accumulating in recent years.Nowadays,quite a lot of researches about microtubule cytoskeleton and other organelles of ciliates living in water have been carried out,while there are few reports on soil ciliates microtubule cytoskeleton,except of that on some small-sizedones.Pattersoniella vitiphila,a large body soil ciliate,was adopted as material to study the microtubule cytoskeleton and other organelles with the help of protargol staining,flutax fluorescent labeling,scanning electron microscopy and transmission electron microscopy.Some information on both micro-and ultra-structure level was obtained.The morphology feature of cirri basal microtubules and other organelles were discussed.The result will contribute to the cell structure characteristics studyof ciliates living in soil.1 Microscopic observation on microtubule cytoskeleton morphology of P.vitiphilaThe cortical ciliature microtubular organelles of P.vitiphila were visualized by flutax direct fluorescent labeling,and it contains adoral zone membranelles,undulating membranelles,frontal-ventral-transverse cirri,migrate cirri,left and right marginal cirri,and dorsal kineties.Adoral zone basal microtubules were located in the base of adoral zone membranelles and undulating membranelles.It was found that the anterior longitudinal microtubules and the posterior longitudinal microtubules were located in the basal part of frontal cirri.The radiate microtubules presented in the basal part of migrate cirri and ventral cirri,and the basal part of migrate cirri also contained posterior longitudinal microtubules.Anterior longitudinal microtubules were discovered in the basal part of transverse cirri.The anterior longitudinal microtubules,posterior longitudinal microtubules,transverse microtubules,radiate microtubules and sprout microtubules were visualized in the basal part of marginal cirri.The anterior longitudinal microtubule and posterior longitudinal microtubule were settled in the basal part of dorsal cirri.The cortical ciliatures and basal fiber of P.vitiphila that viewed by protargol staining were in accordance with the distribution pattern of cortical microtubule organelles that showed by flutax fluorescent labeling,so we speculate that they are the same structure.P.vitiphila was attributed to the family Oxytrichidea,while the arrangement of cirri was quite different from ciliates that living in water,i.e.,its frontal-ventral-transverse cirri model was not following"8-5-5" pattern.The left and right marginal cirri basal microtubules were similar to the feature that found in other soil ciliates.It is suggested that P.vitiphila might possess characteristics that suit with soil environment.The basal part of ventral cirri only contains radial microtubules,and the other kind of microtubules were not found,so it is worthy to explore that whether radial microtubule is a kind of special microtubule in ciliate evolution.2 Ultrastructure of P.vitiphila cortical microtubules and cytoplasmic organellesScanning electron microscopy and transmission electron microscopy showed that the adoral zone membrane of P.vitiphilawerecomposed by little pieces of membranes.Each piece of membrane has 4 columns of cilia,and the quantity of cilia in every column was different.The basal part of cirri was composed by regularity arrangement basal bodies,and some none-cilia affiliated basal bodies were located on one side.The pellicle contains plasma membrane and two pieces of alveolus membranes.Lots of microtubules located in different areas of sub-pellicle.There are two kinds of cytoplasmic,gel structure and sols structure.The mitochondria was located in the gel structure,while membrane vacuole,food vacuole,endoplasmic reticulum were located in the sols structure.The sols structure of cytoplasm was divided into different sections by membrane structures.The rich sub-pellicle microtubules and diversity membrane structures in cell of P.vitiphila do not present in that of water ciliates.These characteristics might suit with the humidity change of soil environment.The rich sub-pellicle microtubules might help P.vitiphila moving in soil environment,and the membrane structures in cytoplasm might related to organelles re-use and autophagy when P.vitiphila forms resting encystment,so it was suspected that the cell characteristics of P.vitiphila might suit with its soil environment.