scholarly journals A simple method for studying nuclear division in free-living soil amoebae.

1972 ◽  
Vol 25 (3) ◽  
pp. 271-272 ◽  
Author(s):  
A Jamieson ◽  
K Anderson
Keyword(s):  
Nuclear Division ◽  
Free Living ◽  
Simple Method

Comparative Analysis Between Paramecium Strains with Different Syngens Using the RAPD Method

2021 ◽  
Author(s):  
Sonoko Matsumoto ◽  
Kenta Watanabe ◽  
Akiko Imamura ◽  
Masato Tachibana ◽  
Takashi Shimizu ◽  
...  
Keyword(s):  
Rapd Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Mating Types ◽  
Genetic Classification ◽  
Reaction Conditions ◽  
Free Living ◽  
Simple Method ◽  
Specific Band ◽  
Freshwater Environments

Abstract Paramecium spp. is types of free-living protists that live in freshwater environments. They are ciliates with high motility and phagocytosis and have been used to analyze cell motility and as a host model for pathogens. Besides such biological characteristics, apart from the usual morphological and genetic classification of species, the existence of taxonomies (such as syngens) and mating types related to Paramecium’s unique reproduction is known. In this study, we attempted to develop a simple method to identify Paramecium strains, which are difficult to distinguish morphologically, using random amplified polymorphic DNA (RAPD) analysis. Consequently, we can observe strain-specific band patterns. We also confirm that the presence of endosymbiotic Chlorella cells affects the band pattern of P. bursaria. Furthermore, the results of the RAPD analysis using several P. caudatum strains with different syngens show that it is possible to detect a band specific to a certain syngen. By improving the reaction conditions and random primers, based on the results of this study, RAPD analysis can be applied to the identification of Paramecium strains and their syngen confirmation tests.

scholarly journals Nuclear division in nine species of small free-living amoebae and its bearing on the classification of the order Amoebida

1952 ◽  
Vol 236 (636) ◽  
pp. 405-461 ◽  
Keyword(s):  
Nuclear Division ◽  
New Method ◽  
Free Living ◽  
Cultural Conditions ◽  
Naegleria Gruberi

A study of nine species of small free-living amoebae has been made under standardized and reproducible cultural conditions, by a new method that enables specimens in all stages of division to be obtained easily. In all species the resting nucleus shows a Feulgen-negative nucleolus and Feulgen-positive chromatin granules. Nuclear division in these species and in other amoebae described by other workers is of two main types on which it is proposed to create two new families— Schizopyrenidae and Hartmannellidae. In Schizopyrenidae, the type genus Schizopyrenus n.g. and two other genera, Naegleria and Didascalus n.g., are defined. Naegleria gruberi, Didascalus thorntoni n.sp., Schizopyrenus russelli n.sp., S. erythaenusa n.sp. and S. atopus n.sp. are described. In Hartmannellidae the type genus Hartmannella is defined. H. glebae, H. rhysodes n.sp., H. leptocnemus n.sp and H. agricola are described. The relation of the proposed classification to previously defined families and genera of amoebae, and its bearing on phylogeny are discussed.

scholarly journals AN UNUSUAL MITOTIC MECHANISM IN THE PARASITIC PROTOZOAN SYNDINIUM SP

1974 ◽  
Vol 60 (3) ◽  
pp. 702-720 ◽  
Author(s):  
Hans Ris ◽  
Donna F. Kubai
Keyword(s):  
Nuclear Envelope ◽  
Nuclear Division ◽  
Specific Area ◽  
Nuclear Space ◽  
Dense Layer ◽  
Nuclear Surface ◽  
Free Living ◽  
Central Spindle ◽  
Cytoplasmic Channel ◽  
Sister Kinetochore

Syndinium and related organisms which parasitize a number of invertebrates have been classified with dinoflagellates on the basis of the morphology of their zoospores. We demonstrate here that with respect to chromosome structure and chemistry as well as nuclear division, they differ fundamentally from free-living dinoflagellates. Alkaline fast green staining indicates the presence of basic proteins in Syndinium chromosomes. Chromatin fibers are about 30 Å thick and do not show the arrangement characteristic of dinoflagellate chromosomes. The four V-shaped chromosomes are permanently attached at their apexes to a specific area of the nuclear membrane through a kinetochore-like trilaminar disk inserted into an opening of the membrane. Microtubules connect the outer dense layer of each kinetochore to the bases of the two centrioles located in a pocket-shaped invagination of the nuclear envelope. During division kinetochores duplicate, and each sister kinetochore becomes attached to a different centriole. As the centrioles move apart, apparently pushed by a bundle of elongating microtubules (central spindle), the daughter chromosomes are passively pulled apart. During the process of elongation of the central spindle, the cytoplasmic groove on the nuclear surface which contains the central spindle sinks into the nuclear space and is transformed into a cylindrical cytoplasmic channel. A constriction in the persisting nuclear envelope leads to the formation of two daughter nuclei.

Studies on pathogenic and non-pathogenic small free-living amoebae and the bearing of nuclear division on the classification of the order Amoebida

1970 ◽  
Vol 259 (832) ◽  
pp. 435-476 ◽  
Keyword(s):  
Systematic Study ◽  
Nuclear Division ◽  
Free Living ◽  
Cultural Conditions ◽  
Indian Soils

A systematic study of small free-living amoebae has been made under standardized and reproducible cultural conditions, and their pathogenicity has been tested in mice. Naegleria aerobia, Hartmannella culbertsoni and H. rhysodes are pathogenic; H. castellanii, H. astronyxis, H. palestinensis, H. glebae, H. exundans, H. vermiformis, Schizopyrenus russelli, Didascalus thorntoni and Tetramitus rostratus are non-pathogenic. Strains of H. culbertsoni and H. rhysodes are present in Indian soils. A classification of the order Amoebida Kent into families Schizopyrenidae Singh, Hartmannellidae Volkonsky, 1931 emend. Singh, 1952, and Endamoebidae (Calkins), based on nuclear division, is proposed, and the relation of this classification to previously defined families and genera of amoebae and its bearing on phylogeny are discussed. Metronidazole and other anti-amoebic drugs are ineffective against N. aerobia and H. culbertsoni in vitro and in meningo-encephalitis in mice.

A simple way for producing holographic filters suitable for image improvement

1978 ◽  
Vol 36 (1) ◽  
pp. 226-227
Author(s):  
K.-H. Herrmann ◽  
E. Reuber ◽  
P. Schiske
Keyword(s):  
Transfer Functions ◽  
Diffraction Order ◽  
Lateral Position ◽  
Simple Method ◽  
Spatial Frequencies ◽  
Resolution Electron ◽  
Wiener Filters ◽  
Image Improvement ◽  
Optical Reconstruction ◽  
Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

Rotary Beveling for In Situ Thin-Section Microscopy of Cell Cultures

1981 ◽  
Vol 39 ◽  
pp. 550-551
Author(s):  
Dean A. Handley ◽  
Jack T. Alexander ◽  
Shu Chien
Keyword(s):  
Cell Growth ◽  
Cell Cultures ◽  
Molecular Interactions ◽  
Convenient Method ◽  
Petri Dish ◽  
Simple Method ◽  
Thin Section Microscopy ◽  
Thin Sectioning ◽  
Organic Fluids

In situ preparation of cell cultures for ultrastructural investigations is a convenient method by which fixation, dehydration and embedment are carried out in the culture petri dish. The in situ method offers the advantage of preserving the native orientation of cell-cell interactions, junctional regions and overlapping configurations. In order to section after embedment, the petri dish is usually separated from the polymerized resin by either differential cryo-contraction or solvation in organic fluids. The remaining resin block must be re-embedded before sectioning. Although removal of the petri dish may not disrupt the native cellular geometry, it does sacrifice what is now recognized as an important characteristic of cell growth: cell-substratum molecular interactions. To preserve the topographic cell-substratum relationship, we developed a simple method of tapered rotary beveling to reduce the petri dish thickness to a dimension suitable for direct thin sectioning.

Ultrastructure of neuromuscular relationships in the canine heartworm (dirofilaria immitis)

1986 ◽  
Vol 44 ◽  
pp. 278-279
Author(s):  
W. L. Steffens ◽  
Nancy B. Roberts ◽  
J. M. Bowen
Keyword(s):  
Dirofilaria Immitis ◽  
Domestic Dogs ◽  
Structural Description ◽  
Pharmacological Effects ◽  
Free Living ◽  
Canine Heartworm ◽  
The World ◽  
Synaptic Region ◽  
Muscle Innervation ◽  
Insight Into

The canine heartworm is a common and serious nematode parasite of domestic dogs in many parts of the world. Although nematode neuroanatomy is fairly well documented, the emphasis has been on sensory anatomy and primarily in free-living soil species and ascarids. Lee and Miller reported on the muscular anatomy in the heartworm, but provided little insight into the peripheral nervous system or myoneural relationships. The classical fine-structural description of nematode muscle innervation is Rosenbluth's earlier work in Ascaris. Since the pharmacological effects of some nematacides currently being developed are neuromuscular in nature, a better understanding of heartworm myoneural anatomy, particularly in reference to the synaptic region is warranted.

Development of a simple method for the determination of single nucleotide polymorphisms

2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Simple Method ◽  
Single Nucleotide
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