scholarly journals BASAL BODIES OF BACTERIAL FLAGELLA IN PROTEUS MIRABILIS

1966 ◽  
Vol 31 (3) ◽  
pp. 585-602 ◽  
Author(s):  
Woutera van Iterson ◽  
Judith F. M. Hoeniger ◽  
Eva Nijman van Zanten
Keyword(s):  
Proteus Mirabilis ◽  
Cell Walls ◽  
Basal Bodies ◽  
Distilled Water ◽  
Proteus Vulgaris ◽  
Fixation Technique ◽  
Previous Suggestion ◽  
Thin Sections ◽  
Bacterial Flagella ◽  
Whole Mount

Years ago (16, 18, 19), in a study of shadowed preparations of Proteus vulgaris that had been autolyzed in the cold, the observation was made that the flagella arose from basal bodies. However, recently (3, 7, 24, 33) doubt has been cast on the conclusion that the flagella of bacteria emerge from sizable basal bodies. This problem has, therefore, been reinvestigated with actively developing cultures of Proteus mirabilis, the cell walls of which had been expanded slightly by exposure to penicillin. Two techniques were applied: ultramicrotomy, and negative staining of whole mount preparations. This paper deals with the thin sections of bacteria after the usual fixation technique had been altered slightly: the cells were embedded in agar prior to their fixation and further processing. The flagella then remained attached to the cells and were seen to extend between the cell wall and the plasma membrane. Occasionally, the flagella appeared to be anchored in the cell by means of a hook-shaped ending. In sections of cells rich in cytoplasm, the basal bodies are particularly difficult to visualize due to their small size (25 to 45 mµ) and the lack of properties that would enable one to distinguish them from the ribonucleoprotein structures; in addition, their boundary appears to be delicate. However, when the cytoplasm is sparse in the cells, either naturally or as a result of osmotic shocking in distilled water, the flagella can be observed to emerge from rounded structures approximately 25 to 45 mµ wide. Contrary to a previous suggestion (21), the flagella do not terminate in the peripheral sites of reduced tellurite, i.e. the chondrioids. The observations in this part of the study agree with those described in the following paper (15) dealing with negatively stained preparations.

scholarly journals BASAL BODIES OF BACTERIAL FLAGELLA IN PROTEUS MIRABILIS

1966 ◽  
Vol 31 (3) ◽  
pp. 603-618 ◽  
Author(s):  
Judith F. M. Hoeniger ◽  
Woutera van Iterson ◽  
Eva Nijman van Zanten
Keyword(s):  
Plasma Membrane ◽  
Proteus Mirabilis ◽  
Basal Bodies ◽  
Previous Suggestion ◽  
Potassium Tellurite ◽  
Bacterial Flagella ◽  
Left Behind ◽  
Potassium Phosphotungstate ◽  
Cytoplasmic Content

This paper investigates further the question of whether the flagella of Proteus mirabilis emerge from basal bodies. The bacteria were grown to the stage of swarmer differentiation, treated lightly with penicillin, and then shocked osmotically. As a result of this treatment, much of the cytoplasmic content and also part of the plasma membrane were removed from the cells. When such fragmented organisms were stained negatively with potassium phosphotungstate, the flagella were found to be anchored—often by means of a hook—in rounded structures approximately 50 mµ wide, thus confirming Part I of our study. In these rounded structures a more brilliant dot was occasionally observed, which we interpret as being part of the basal granule. A prerequisite for the demonstration of the basal granules within the cells was, however, the removal of both the cytoplasm and the plasma membrane from their vicinity. In some experiments, the chondrioids were "stained" positively by the incorporation into them of the reduced product of potassium tellurite. The chondrioids were here observed to be more or less circular areas from which rodlike structures extended. The chondrioids adhered so firmly to the plasma membrane that they were carried away with it during its displacement by osmotic shocking, while the basal bodies were left behind. This observation disproves our previous suggestion that the flagella might terminate in the chondrioids. The basal bodies often occur in pairs, which suggest that they could be self-reproducing particles.

scholarly journals A "MICROTUBULE" IN A BACTERIUM

1967 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Woutera van Iterson ◽  
Judith F. M. Hoeniger ◽  
Eva Nijman van Zanten
Keyword(s):  
Proteus Mirabilis ◽  
Normal Cell ◽  
Osmotic Shock ◽  
Hollow Core ◽  
Cylindrical Wall ◽  
Thin Sections ◽  
Whole Mount ◽  
Potassium Phosphotungstate ◽  
First Time ◽  
Cell Constituent

A study of the anchorage of the flagella in swarmers of Proteus mirabilis led to the incidental observation of microtubules. These microtubules were found in thin sections and in whole mount preparations of cells from which most of the content had been released by osmotic shock before staining negatively with potassium phosphotungstate (PTA). The microtubules are in negatively stained preparations about 200 A wide, i.e. somewhat thicker than the flagella (approximately 130 A). They are thus somewhat thinner than most microtubules recorded for other cells. They are referred to as microtubules because of their smooth cylindrical wall, or cortex, surrounding a hollow core which is readily filled with PTA when stained negatively. Since this is probably the first time that such a structure is described inside a bacterium, we do not know for certain whether it represents a normal cell constituent or an abnormality, for instance of the type of "polysheaths" (16).

scholarly journals The basal bodies of Chlamydomonas reinhardtii. Formation from probasal bodies, isolation, and partial characterization.

1975 ◽  
Vol 65 (1) ◽  
pp. 65-74 ◽  
Author(s):  
R R Gould
Keyword(s):  
Electron Microscopy ◽  
Chlamydomonas Reinhardtii ◽  
Basal Body ◽  
Sodium Dodecyl ◽  
Basal Bodies ◽  
Polyethylene Glycol 400 ◽  
Thin Sections ◽  
Particulate Contamination ◽  
Whole Mount ◽  
Carbon Coated

The assembly and composition of basal bodies was investigated in the single-celled, biflagellate green alga, Chlamydomonas reinhardtii, using the cell wall-less strain, cw15. In the presence of EDTA, both flagellar axonemes remained attached to their basal bodies while the entire basal body-axoneme complex was separated from the cell body, without cell lysis, by treatment with polyethylene glycol-400. The axonemes were then removed from the basal bodies in the absence of EDTA, leaving intact basal body pairs, free from particulate contamination from other regions of the cell. The isolated organelles produced several bands on sodium dodecyl sulfate-urea polyacrylamide gels, including two tubilin bands which co-electrophoresed with flagellar tubulin. The formation of probasal bodies was observed by electron microscopy of whole mount preparations. Synchronous cells were lysed, centrifuged onto carbon-coated grids, and either negatively stained or shadowed with platinum. The two probasal bodies of each cell appeared shortly after mitosis as thin "annuli," not visible in thin sections, each consisting of nine rudimentary triplet microtubules. Each annulus remained attached to one of the mature basal bodies by several filaments about 60 in diameter, and persisted throughout interphase until just before the next cell division. It then elongated into a mature organelle. The results revive the possibility of the nucleated assembly of basal bodies.

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

A rapid silver-impregnation technique on ultra-thin sections for Electron Microscopy

1993 ◽  
Vol 51 ◽  
pp. 242-243
Author(s):  
K. Chien ◽  
R.C. Heusser ◽  
M.L. Jones ◽  
R.L. Van de Velde
Keyword(s):  
Electron Microscopy ◽  
Silver Nitrate ◽  
Silver Impregnation ◽  
Sodium Borate ◽  
Renal Diseases ◽  
Distilled Water ◽  
Thin Sections ◽  
Impregnation Technique ◽  
Centrifuge Tube ◽  
Simplified Procedure

Silver impregnation techniques have been used for the demonstration of the complex carbohydrates in electron microscopy. However, the silver stains were believed to be technically sensitive and time consumming to perform. Currently, due to the need to more specifically evaluate immune complex for localization in certain renal diseases, a simplified procedure in conjunction with the use of the microwave has been developed and applied to renal and other biopsies. The procedure is as follows:Preparation of silver methenamine solution:1. 15ml graduated, clear polystyrene centrifuge tube (Falcon, No. 2099) was rinsed once with distilled water.2. 3% hexamethylene tetramine (methenamine) was added into the centrifuge tube to the 6ml mark.3. 3% silver nitrate was added slowly to the methenamine to the 7ml mark while agitating. (Solution will instantly turn milky in color and then clear rapidly by mixing. No precipitate should be formed).4. 2% sodium borate was added to the solution to the 8ml mark, mixed and centrifuged before use.

scholarly journals FINE STRUCTURE OF THE GRAM-NEGATIVE BACTERIUM ACETOBACTER SUBOXYDANS

1964 ◽  
Vol 20 (2) ◽  
pp. 217-233 ◽  
Author(s):  
G. W. Claus ◽  
L. E. Roth
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Walls ◽  
Negative Staining ◽  
Homogeneous Layer ◽  
Physical Treatment ◽  
Thin Sections ◽  
Gram Negative ◽  
Acetobacter Suboxydans ◽  
Negative Cell

The morphological features of the cell wall, plasma membrane, protoplasmic constituents, and flagella of Acetobacter suboxydans (ATCC 621) were studied by thin sectioning and negative staining. Thin sections of the cell wall demonstrate an outer membrane and an inner, more homogeneous layer. These observations are consistent with those of isolated, gram-negative cell-wall ghosts and the chemical analyses of gram-negative cell walls. Certain functional attributes of the cell-wall inner layer and the structural comparisons of gram-negative and gram-positive cell walls are considered. The plasma membrane is similar in appearance to the membrane of the cell wall and is occasionally found to be folded into the cytoplasm. Certain features of the protoplasm are described and discussed, including the diffuse states of the chromatinic material that appear to be correlated with the length of the cell and a polar differentiation in the area of expected flagellar attachment. Although the flagella appear hollow in thin sections, negative staining of isolated flagella does not substantiate this finding. Severe physical treatment occasionally produces a localized penetration into the central region of the flagellum, the diameter of which is much smaller then that expected from sections. A possible explanation of this apparent discrepancy is discussed.

Ultrastructural comparisons of fungus hyphal cells using frozen-etched replicas and thin sections of the fungus Pyrenochaeta terrestris

1968 ◽  
Vol 14 (3) ◽  
pp. 205-210 ◽  
Author(s):  
W. M. Hess
Keyword(s):  
Electron Scattering ◽  
Cell Walls ◽  
Sole Carbon Source ◽  
Membrane Systems ◽  
Thin Sections ◽  
Fixed Membrane ◽  
Pyrenochaeta Terrestris ◽  
Freeze Etching ◽  
Fixed Cell ◽  
Etched Membrane

The ultrastructure of P. terrestris hyphal cells was investigated to compare frozen-etched replicas with chemically fixed thin sections. The fungus used in this study uses glycerol as a sole carbon source and survives the freezing procedures necessary for freeze-etching; thus frozen-etched replicas reflect the living state.Frozen-etched membrane systems have particles of various sizes and concentrations and have a smooth appearance as contrasted to chemically fixed membrane systems, which have particles difficult to distinguish and somewhat irregular membrane systems. Frozen-etched cell walls are seen to contain particles, and microfibrillar orientation is evident in older cell walls, whereas substructure is not evident in chemically fixed cell walls, although secretion products of the fungus accumulate on cell surfaces.Chemically fixed ground cytoplasm has ribosomes and areas of high- and low-electron scattering which are not seen with freeze-etching. Cells fixed in glutaraldehyde–acrolein–OsO4 more nearly resemble frozen-etched cells than cells fixed in potassium permanganate.

scholarly journals Comparative and functional morphology of the mouthparts in larvae of Parasitengona (Acariformes)*

Zoosymposia ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. 14-23 ◽  
Author(s):  
ANDREY B. SHATROV
Keyword(s):  
Functional Morphology ◽  
Ultrastructural Organization ◽  
Functional Specialization ◽  
Evolutionary Trends ◽  
Water Mites ◽  
Dorsal Shield ◽  
Water Mite ◽  
Thin Sections ◽  
Whole Mount

Anatomy and ultrastructural organization of the larval mouthparts in representatives of terrestrial (Trombiculidae parasitizing vertebrates and Microtrombidiidae parasitizing arthropods) as well as aquatic (Pionidae and Hydrodromidae parasitizing arthropods) families from the cohort Parasitengona were studied using whole-mount preparations, semi-thin sections and TEM and SEM methods. In these groups, the organization of the mouth apparatus differs significantly especially with regard to their particular functional specialization and adaptations reflecting evolutionary trends in these groups. In trombiculid larvae, the mouthparts reveal the simplest organization. The gnathosoma is totally free, the infracapitulum and the basal cheliceral segments are short and wide, and the latter are separated from each other. The flexible lateral lips form a temporary sucker, distinguishable when the larva feeds, and the pharynx is totally fused with the bottom of the infracapitulum. In microtrombidiid larvae, the gnathosoma is covered by the arched dorsal shield, the chelicerae are comparatively long and separated, and the lateral lips form a permanent sucker provided with an internal sclerite. Conversely, in water mite larvae, the chelicerae are fused together and either partially (Piona carnea) or totally (Hydrodroma despiciens) free from the overhanging idiosomal fold. The lateral lips are flexible and organized freely, and the pharynx is totally separated from the bottom of the infracapitulum. In general, water mite larvae show significant variations and specializations but at the same time seem to possess the most plesiomorphic characters in organization of the mouth apparatus. The ancestral parasitengone may have given rise to divergent groups of water mites as such, as well as to trombiculids with the secondary simplification of the mouth apparatus and to microtrombidiids with their particular additional adaptations and specialization in organization of the mouthparts.

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