scholarly journals DNA AND THE FINE STRUCTURE OF SYNAPTIC CHROMOSOMES IN THE DOMESTIC ROOSTER (GALLUS DOMESTICUS)

1964 ◽  
Vol 23 (1) ◽  
pp. 63-78 ◽  
Author(s):  
James R. Coleman ◽  
Montrose J. Moses
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Fine Structure ◽  
Electron Microscope ◽  
Meiotic Prophase ◽  
Gallus Domesticus ◽  
Feulgen Staining ◽  
Synaptinemal Complex ◽  
Relationship Of ◽  
The Relationship

The indium trichloride method of Watson and Aldridge (38) for staining nucleic acids for electron microscopy was employed to study the relationship of DNA to the structure of the synaptinemal complex in meiotic prophase chromosomes of the domestic rooster. The selectivity of the method was demonstrated in untreated and DNase-digested testis material by comparing the distribution of indium staining in the electron microscope to Feulgen staining and ultraviolet absorption in thicker sections seen with the light microscope. Following staining by indium, DNA was found mainly in the microfibril component of the synaptinemal complex. When DNA was known to have been removed from aldehyde-fixed material by digestion with DNase, indium stainability was also lost. However, staining of the digested material with non-selective heavy metal techniques demonstrated the presence of material other than DNA in the microfibrils and showed that little alteration in appearance of the chromosome resulted from DNA removal. The two dense lateral axial elements of the synaptinemal complex, but not the central one to any extent, also contained DNA, together with non-DNA material.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The flagellar apparatus in zoospores of Phytophthora, Pythium, and Halophytophthora

1992 ◽  
Vol 70 (11) ◽  
pp. 2163-2169 ◽  
Author(s):  
D. J. S. Barr ◽  
N. L. Désaulniers
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Flagellar Apparatus ◽  
Posterior Root ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Cytoplasmic Microtubules ◽  
Relationship Of ◽  
The Relationship

The flagellar apparatuses of 14 species of Phytophthora, 2 of Halophytophthora, and 4 of Pythium are compared in the transmission electron microscope. Except for Phytophthora infestans and Phytophthora mirabilis there were no significant differences in fine structure morphology. There are six flagellar roots: a ribbed triplet consisting of three main microtubules and secondary microtubules; an anterior doublet; a multistranded, band-shaped root of five to nine microtubules; a posterior root of two to four microtubules; and roots consisting of arrays of cytoplasmic microtubules and nuclear-associated microtubules. In P. infestans and P. mirabilis the multistranded root is missing, the posterior root contains five or six microtubules, and the anterior ribbed root contains four main microtubules. The transitional zones in all species are similar. The relationship of the Pythiaceae with other Oomycetes is discussed. Key words: taxonomy, phytogeny, cytology, Oomycetes, Pythiaceae.

The nature of the internal fine structure of Rhodopseudomonas splieroides as determined by the study of cell fragments

1968 ◽  
Vol 170 (1020) ◽  
pp. 255-263 ◽  
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Ionic Strength ◽  
Cytoplasmic Membrane ◽  
Covalent Bonding ◽  
High Ionic Strength ◽  
Rhodopseudomonas Spheroides ◽  
Relationship Of ◽  
The Relationship ◽  
Cell Fragments

Treatment of Rhodopseudomonas spheroides with lysozyme and versene, followed by the application of mild shearing forces, has enabled the visualization by electron microscopy of the relationship of ehromatophores to the cytoplasmic membrane. Pigmented fragments were isolated also and on centrifuging in sucrose density gradients their properties were identical with those of chromatophores from cells disrupted by more vigorous methods. Since prolonged freezing of the cells or the presence of media of high ionic strength were required to obtain these results it is concluded that non-covalent bonding is of importance in holding the chromatophores to the rest of the cytoplasmic membrane.

Binding of Tetrahymena dynein to axonemes of Marsilea vestita lacking the outer dynein arm

1985 ◽  
Vol 73 (1) ◽  
pp. 299-310
Author(s):  
J.S. Hyams
Keyword(s):  
Electron Microscopy ◽  
Polyacrylamide Gel Electrophoresis ◽  
Valuable Insight ◽  
Marsilea Vestita ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
And Function ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Axonemes from the heterosporous water fern Marsilea vestita were fixed in the presence of tannic acid and examined by thin-section electron microscopy. Transverse sections revealed the normal 9+2 configuration except for the absence of the outer of the two dynein arms. Both arms were normally preserved in parallel preparations of Chlamydomonas axonemes. Isolated dynein from the ciliated protozoon Tetrahymena bound to Marsilea axonemes at the site normally occupied by the outer arm. Dynein binding was partially reversed by ATP as judged by both electron microscopy and polyacrylamide gel electrophoresis. This system should provide a valuable insight into the biochemistry and function of the inner dynein arm and the relationship of the two arms to motility in more conventionally equipped axonemes.

scholarly journals The Relationship of Bartonella Bacilliformis to the Red Blood Cell as Revealed by Electron Microscopy

Blood ◽  
1969 ◽  
Vol 33 (5) ◽  
pp. 708-716 ◽  
Author(s):  
MANUEL CUADRA ◽  
JUAN TAKANO
Keyword(s):  
Electron Microscopy ◽  
Blood Cell ◽  
Red Cells ◽  
Red Cell ◽  
Bartonella Bacilliformis ◽  
Coccoid Form ◽  
Blood Smears ◽  
Ultrathin Sections ◽  
Relationship Of ◽  
The Relationship

Abstract Ultrathin sections of erythrocytosis parasitized by B. bacilliformis have been examined by electron microscopy. The study concerns three Oroya Fever patients whose blood smears showed B. bacilliformis predominantly in its coccoid form as parastizing over 70 per cent of the red cells. B. bacilliformis is termed as a bacterium in its structure and appears to lie not only on the host red cells but predominantly within them. Therefore, this organism might have the capacity to penetrate into the red cell. This finding does not change the basic concept regarding the mechanism of the anemia of Oroya Fever.

The fine structure of the vertical lobe of Octopus brain

1970 ◽  
Vol 258 (827) ◽  
pp. 379-394 ◽  
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Synaptic Vesicles ◽  
Structural Organization ◽  
Amacrine Cells ◽  
Large Cell ◽  
Inhibitory Effect ◽  
Tactile System

Although much is known about the structural organization and connexions of the various lobes of the octopus brain from light microscopy, this is the first attempt at a detailed analysis of one of the lobes— the vertical lobe, with the electron microscope. The vertical lobe consists of five lobules. The median superior frontal (MSF) axons enter each lobule from the MSF lobe. The MSF axons contain both microtubules and neurofilaments. The varicosities of the MSF axons contain both agranular and dense-cored vesicles and synapse with trunks of the amacrine cells. These trunks run together in bundles termed amacrine tracts into the centres of the lobules. The amacrine trunks contain microtubules but no neurofilaments. The trunks contain large and small agranular synaptic vesicles and synapse with what are in all probability branches of the trunks of the large cells. These trunks contain microtubules but no neurofilaments. They run out through the bases of the lobules probably without forming synaptic contacts within the lobule. Fibres signalling ‘pain’ (nocifensor) enter the lobules from below. They can be recognized by their content of neurofilaments. Their terminals contain numerous very small synaptic vesicles and a few larger and dense-cored ones. These ‘pain’ fibres appear to synapse mostly with processes of the large cells. J. Z. Young has shown that the vertical lobe is especially concerned with the integrative action of the visual system, linked with the chemo-tactile system. Electron microscopy supports Young’s suggestion that the superior frontal and interconnected vertical lobe systems constitute a loop which could sustain a positive feed-back mechanism (MSF —> amacrine -> large cell -> lateral superior frontal -> MSF) while the ‘pain’ (nocifensor) input could exert a suppressor (inhibitory) effect on the loop by its action on the large cells.

scholarly journals THE EFFECT OF INSULIN, ALLOXAN DIABETES, AND ANOXIA ON THE ULTRASTRUCTURE OF THE RAT HEART

1962 ◽  
Vol 15 (3) ◽  
pp. 509-523 ◽  
Author(s):  
David N. Orth ◽  
Howard E. Morgan
Keyword(s):  
Electron Microscopy ◽  
Glucose Transport ◽  
Alloxan Diabetes ◽  
Diabetic Rats ◽  
Cytoplasmic Vesicles ◽  
Lipid Inclusions ◽  
Line Level ◽  
Relationship Of ◽  
The Relationship

Hearts from normal and alloxan diabetic rats were perfused in vitro with a bicarbonate-buffered medium containing glucose. Transport of glucose through the cell membrane was stimulated with insulin or by induction of anaerobiosis. The organs were rapidly fixed and examined by electron microscopy. Transport stimulation was not associated with any increase in the number of sarcolemmal invaginations or subsarcolemmal cytoplasmic vesicles. It was concluded that glucose transport and the effects of insulin or anoxia do not involve pinocytosis. The relationship of pinocytosis to glucose transport is discussed. The appearance of numerous lipid inclusions at the Z line level of the sarcomeres in the diabetic and anoxic myocardia is described.

Fine structure of granulated cells in the posterior cardinal and renal veins of Amia calva L.

1976 ◽  
Vol 54 (6) ◽  
pp. 843-851 ◽  
Author(s):  
John H. Youson
Keyword(s):  
Fine Structure ◽  
Secretory Granules ◽  
Immediate Release ◽  
Nerve Terminals ◽  
Renal Veins ◽  
Subendothelial Space ◽  
Secretory Products ◽  
Amia Calva ◽  
Relationship Of ◽  
The Relationship

Granulated cells located in the walls of the posterior cardinal and renal veins in the holostean fish Amia calva resemble cells of the adrenal medulla of higher vertebrates. The cells all contain similar electron-dense secretory granules, apparently originating from the Golgi apparatus, and are innervated by nerve terminals. These features suggest that the cells are involved in the production and release of catecholamines. The relationship of the cells to the endothelium of the large veins also suggests that the secretory products of the cells reach the circulation by traversing a complex subendothelial space and passing through the fenestrae of the endothelium. This appears to be an efficient means for the immediate release and distribution of catecholamines in this species of fish.

scholarly journals CENTROSOMES AND MICROTUBULES DURING MEIOSIS IN THE MUSHROOM BOLETUS RUBINELLUS

1971 ◽  
Vol 50 (3) ◽  
pp. 737-745 ◽  
Author(s):  
David J. McLaughlin
Keyword(s):  
Electron Microscope ◽  
Longitudinal Axis ◽  
Spindle Pole ◽  
Middle Part ◽  
Prophase I ◽  
Cytoplasmic Microtubules ◽  
Oriented Parallel ◽  
Relationship Of ◽  
The Relationship

The double centrosome in the basidium of Boletus rubinellus has been observed in three planes with the electron microscope at interphase preceding nuclear fusion, at prophase I, and at interphase I. It is composed of two components connected by a band-shaped middle part. At anaphase I a single, enlarged centrosome is found at the spindle pole, which is attached to the cell membrane. Microtubules mainly oriented parallel to the longitudinal axis of the basidium are present at prefusion, prophase I and interphase I. Cytoplasmic microtubules are absent when the spindle is present. The relationship of the centrosome in B. rubinellus to that in other organisms and the role of the cytoplasmic microtubules are discussed.

Sign in / Sign up

Export Citation Format

Share Document