Fine Structure Interphase Cell and Cell Organelles

1970 ◽  
pp. 9-38
Author(s):  
Myron C. Ledbetter ◽  
Keith R. Porter
Keyword(s):  
Fine Structure ◽  
Cell Organelles ◽  
Interphase Cell

Cell Fine Structure as Revealed in Dessicator-Dried Resinless Sections

1981 ◽  
Vol 39 ◽  
pp. 622-623
Author(s):  
R. P. Becker ◽  
J. J. Wolosewick ◽  
J. Ross-Stanton
Keyword(s):  
Fine Structure ◽  
Tannic Acid ◽  
Three Dimensional ◽  
Albino Rats ◽  
Cell Organelles ◽  
Vascular Perfusion ◽  
Thin Sections ◽  
Carbon Coated ◽  
Embedding Medium ◽  
Polyethylene Glycol 6000

Methodology has been introduced recently which allows transmission and scanning electron microscopy of cell fine structure in semi-thin sections unencumbered by an embedding medium. Images obtained from these “resinless” sections show a three-dimensional lattice of microtrabeculfee contiguous with cytoskeletal structures and membrane-bounded cell organelles. Visualization of these structures, especially of the matiiDra-nous components, can be facilitated by employing tannic acid in the fixation step and dessicator drying, as reported here.Albino rats were fixed by vascular perfusion with 2% glutaraldehyde or 1.5% depolymerized paraformaldehyde plus 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4). Tissues were removed and minced in the fixative and stored overnight in fixative containing 4% tannic acid. The tissues were rinsed in buffer (0.2M cacodylate), exposed to 1% buffered osmium tetroxide, dehydrated in ethyl alcohol, and embedded in pure polyethylene glycol-6000 (PEG). Sections were cut on glass knives with a Sorvall MT-1 microtome and mounted onto poly-L-lysine, formvar-carbon coated grids while submerged in a solution of 95% ethanol containing 5% PEG.

Ultrastructural changes in the midgut epithelium of an elaterid larva (Coleoptera) infected enterically with Pseudomonas aeruginosa

1973 ◽  
Vol 19 (7) ◽  
pp. 811-821 ◽  
Author(s):  
R. Y. Zacharuk
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Fine Structure ◽  
Midgut Epithelium ◽  
Ultrastructural Changes ◽  
Pathological Changes ◽  
Cell Organelles ◽  
Selective Permeability ◽  
Potential Pathogen ◽  
Membrane Bound ◽  
Cytoplasmic Ribosomes

Soil bacteria enter the digestive tract of wireworms at ecdysis through the dorsal exuvial split and ecdysial space. Pseudomonas aeruginosa, a potential pathogen of insects, multiplies in the enteron, but many are killed within it. The mucopeptide layer of the bacterial cell wall is affected early in the degenerative process.A surface epithelial mucoid layer provides a temporary protective barrier for the midgut epithelium against the bacteria. The bacteria affect the fine structure of the host midgut epithelium in three primary ways. (1) The cells take up and retain fluids in the cytoplasm and membrane-bound vacuoles to the point of apical rupture; the selective permeability of the membranes of the cell and vacuoles appears to be affected. (2) The surface mucoid covering is degraded, the exposed plasma membrane is disrupted, and a lytic erosion of the exposed cytoplasm occurs opposite bacterial colonies. Lesions thus form in the midgut epithelium, and could lead to perforation of the wall at these points. (3) Pathological changes occur in various cell organelles, the most striking of which are an increase in abundance of rough endoplasmic reticulum (RER) and cytoplasmic ribosomes, and a transposition of membrane material from mitochondria and Golgi complexes to RER. The functional implications of these pathological changes in fine structure are discussed.

Fine structure of ocelli of the larval black fly Simulium vittatum (Diptera: Simuliidae)

1987 ◽  
Vol 65 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Joyce M. Nyhof ◽  
Susan B. McIver
Keyword(s):  
Fine Structure ◽  
Polarized Light ◽  
Cell Organelles ◽  
Golgi Bodies ◽  
Simulium Vittatum ◽  
Pigment Granules ◽  
Transmission Electron ◽  
Structural Differences ◽  
Numerous Cell ◽  
Retinular Cells

The fine structure of light- and dark-adapted ocelli of last instar larval Simulium vittatum Zetterstedt was described using scanning and transmission electron microscopy. Larvae have six ocelli arranged in groups of three on each side of the head. The larger two ocelli of each group are externally visible as two darkly pigmented eyespots. The third, smaller ocellus lacks pigmentation and, therefore, is not externally visible. Each ocellus has its long axis oriented dorso-ventrally, has 13 retinular cells, and lacks an expanded cuticular lens. Conspicuous rhabdoms occur in the three ocelli. The rhabdoms of the pigmented ocelli are centrally located and enveloped by pigment granules. The microvilli of the rhabdoms are oriented primarily in one plane, an indication of a possible sensitivity to polarized light. The rhabdom of the unpigmented ocellus is eccentrically located and its microvilli are not uniplanar. Each ocellus has numerous cell organelles, including mitochondria, ribosomes, endoplasmic reticulum, and Golgi bodies. Especially conspicuous are membranous figures, which are associated with the nuclei and vary in size and complexity from simple stacks to lamellar whorls. These latter organelles are probably involved in the turnover processes of the rhabdomeric membranes. In light- and dark-adapted ocelli the only structural differences were associated with the microvilli and multivesicular bodies. Differences in location of pigment granules and in size of rhabdomeres and membranous figures were not observed.

scholarly journals PERMANGANATE FIXATION OF THE GOLGI COMPLEX AND OTHER CYTOPLASMIC STRUCTURES OF MAMMALIAN TESTES

1960 ◽  
Vol 8 (3) ◽  
pp. 761-775 ◽  
Author(s):  
Hilton H. Mollenhauer ◽  
William Zebrun
Keyword(s):  
Fine Structure ◽  
Guinea Pig ◽  
Golgi Complex ◽  
Sertoli Cells ◽  
Close Association ◽  
High Electron ◽  
Cell Organelles ◽  
Different Dimensions ◽  
Morphological Differences ◽  
Cytoplasmic Structures

Observations on the fine structure of KMnO4-fixed testes of small mammals (guinea pig, rat, and mouse) reveal certain morphological differences between the spermatogenic and Sertoli cells which have not been demonstrated in the same tissue fixed with OsO4. Aggregates of minute circular profiles, much smaller than the spherical Golgi vesicles, are described in close association with the Golgi complex of developing spermatids. Groups of dense flattened vesicles, individually surrounded by a membrane of different dimensions than that which bounds most of the other cell organelles, appear dispersed within the cytoplasm of some spermatogenic cells. Flattened vesicles of greater density than those belonging to the Golgi complex are reported confined to the inner Golgi zone of developing guinea pig spermatids between the Golgi cisternae and the head cap. The profiles of endoplasmic reticulum within spermatocytes appear shorter, wider, and more tortuous than those of Sertoli cells. Minute cytoplasmic particles approximately 300 A in diameter and of high electron opacity appear randomly disposed in some Sertoli cells. Groups of irregular-shaped ovoid bodies within the developing spermatids are described as resembling portions of cytoplasm from closely adjacent spermatids. Interpretation is presented regarding the fine structure of KMnO4-fixed testes in view of what has already been reported for mammalian testes fixed in OsO4.

The fine structure of the centriolar apparatus and associated structures in the complex flagellates Trichonympha and Pseudotrichonympha

1966 ◽  
Vol 250 (766) ◽  
pp. 215-242 ◽  
Keyword(s):  
Complex System ◽  
Fine Structure ◽  
Basal Body ◽  
Electron Microscope Study ◽  
Basal Bodies ◽  
Surface Layers ◽  
Interphase Cell ◽  
Fibrous Body ◽  
Radially Polarized ◽  
Spindle Fibres

The centriolar apparatus in the flagellate genera Trichonympha and Pseudotrichonympha is located at the anterior end of the cell, in the rostrum. It forms part of a complex system of structures which includes the rostral tube, inner and outer caps, and the rostral flagella. The fine structure of these organelles is described in detail on the basis of an electron-microscope study of sectioned and negatively stained material. In Trichonympha the rostral tube is a hollow cylinder, made of a cross-striated protein with a periodicity of about 450 Å. This is organized into radially arranged lamellae, which continue posteriorly as the parabasal filaments. The tube is continuous anteriorly with two finely striated crescentic bodies, which correspond to the so-called short centrioles of some previous workers. There is no evidence that they are centriolar in function. In the interphase cell the centriolar apparatus consists principally of a long centriolar rod, of complex fine structure, lying in the anterior end of the rostral tube. There is no evidence of typical centriolar structure in this, but at division an aster forms around one end of it. Surmounting the apex of the rostral tube is a dense, finely fibrous body, the inner cap. Lying within this there is a typical centriole (similar in structure to a basal body), and also the basal body of one flagellum, which appears to be distinct from all the rest. The functions of these two structures are not known. The margin of the inner cap connects with the complex system of delicate fibres which links the basal bodies of the rostral flagella. The function of the fibres, and possibly also of the inner cap, may be to coordinate the activities of the rostral flagella. The outer cap is composed mainly of tubules, 250 Å in diameter, but shows variations in structure in different species. The structures in Pseudotrichonympha which presumably serve similar functions are in many respects very differently organized. The rostral tube is more complex, with distinct inner and outer walls of different fine structure. There are also complex inner and outer surface layers. A striking feature is that although the various components of the tube are quite different in structure, they display a common periodicity in their organization. The centriolar apparatus appears to consist principally of two dense bands running along the inner wall of the tube, connecting anteriorly to an extended layer of centriolar material to which spindle fibres are attached in radially polarized fashion throughout interphase. There is no centriolar rod or typical centriole, such as is found in Trichonympha . Very elaborate systems of fibres are associated with the inner cap and the anterior end of the rostral tube. The two genera are compared, and the findings related to knowledge of centriolar structures in other types of cell. Possible evolutionary explanations for the complexity and variation in fine structure in these flagellates are considered.

On the fine structure of sieve tubes and the physiology of assimilate transport in Alaria marginata

1975 ◽  
Vol 53 (9) ◽  
pp. 861-876 ◽  
Author(s):  
Klaus Schmitz ◽  
L. M. Srivastava
Keyword(s):  
Fine Structure ◽  
Inorganic Ions ◽  
Sieve Tube ◽  
Assimilate Transport ◽  
Cell Organelles ◽  
Long Distance ◽  
Double Labeling ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
Alaria Marginata

Alaria marginata Postels and Ruprecht has a sieve tube system which extends through the lamina, especially the midrib, and through the stipe. The sieve elements originate from the innermost cortex cells and are nucleate, highly vacuolated cells that contain the usual cell organelles and membrane systems. The plastids and mitochondria show some special features in their morphology and fine structure. P protein is absent. Sieve pores, 0.11–0.3 μm in diameter, occur in cross walls between two sieve elements. They are lined by plasmalemma, and the cytoplasms of the two cells are interconnected through them. Long-distance transport of photo-assimilate follows the source–sink relationship; but its normal basipetal direction can be reversed by creating "artificial" sinks. Translocation velocity is in the range of 25 to 40 cm/h. The translocate consists mainly of mannitol and free amino acids, which were analyzed qualitatively and quantitatively. Double-labeling experiments with 32P and 14C indicate that inorganic ions are not translocated together with the 14C-labeled photoassimilates and probably move only by diffusion.

scholarly journals THE FINE STRUCTURE OF OSTEOBLASTS IN THE METAPHYSIS OF THE TIBIA OF THE YOUNG RAT

1961 ◽  
Vol 9 (3) ◽  
pp. 583-595 ◽  
Author(s):  
D. A. Cameron
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Light Microscope ◽  
Bone Matrix ◽  
Organic Matrix ◽  
Striking Feature ◽  
Cell Organelles ◽  
Phosphate Ions ◽  
Fine Structures ◽  
Young Rat

The appearance of osteoblasts after fixation with OsO4 is described in this paper. They have the basic structures found in other types of cells. The most striking feature is the array of rough-surfaced membranes of the endoplasmic reticulum; this feature is in keeping with the osteoblast's function of producing collagen as the bone grows. The sacs formed by these membranes probably represent the protein-containing granules described by other workers using the light microscope. They contain fine fibrillary material, and similar fibrils are to be found free in the cytoplasm. These fibrils could be tropocollagen units, although fibrils recognizable as collagen by their structure are found only outside the cell. The arrangement of the cell organelles does not seem to be related to the formation of collagen, but correlation of the fine structures of the cells with the histochemical and cytochemical findings in these cells reported by other workers leaves no doubt that they are directly concerned in the production of the organic matrix. It has not been possible to show that osteoblasts influence the passage of calcium or phosphate ions from the blood to the bone matrix.

scholarly journals Studies on lolium multiflorum endosperm in tissue culture II. Fine structure of cells and cell walls and the development of cell walls

1973 ◽  
Vol 26 (1) ◽  
pp. 135 ◽  
Author(s):  
DJ Mares ◽  
BA Stone
Keyword(s):  
Tissue Culture ◽  
Fine Structure ◽  
Cell Walls ◽  
Lolium Multiflorum ◽  
Suspension Cultures ◽  
Protein Bodies ◽  
Starch Granules ◽  
Cell Organelles ◽  
Stages Of Growth ◽  
Liquid Suspension

Log phase cells of L. multiflorum endosperm grown in liquid suspension cultures contain large nuclei, mitochondria, protein bodies, compound starch granules, small vacuoles, and multilayered membranous structures. At later stages of growth the cell organelles, protein bodies, and starch granules disappear and in senescent cultures many empty cells are seen.

Ultrastructure of lichen haustoria: symbiosis in Parmelia sulcata

1970 ◽  
Vol 48 (9) ◽  
pp. 1521-1524 ◽  
Author(s):  
Mukta M. Webber ◽  
P. J. Webber
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Algal Cell ◽  
Enzymatic Digestion ◽  
Phylogenetic Significance ◽  
Cell Organelles ◽  
Fungal Cell ◽  
Parmelia Sulcata ◽  
Obligate Mutualism ◽  
A Site

Fine structure of haustoria in Parmelia sulcata Tayl. has been investigated. Electron micrographs show that haustoria of this lichen probably penetrate the algal cells by mechanical as well as biochemical means. Presence of mesosomes and "lysosome-like organelles" in the haustoria suggests that the penetration may be brought about by enzymatic digestion of the algal cell wall and that the fungal cell may further produce enzymes to digest the algal cell contents. Abundance of mitochondria near the haustorial origin indicates a site of increased metabolic activity. If further investigations produce evidence that the "lysosome-like organelles" are true lysosomes, then these findings are of phylogenetic significance with regard to the evolution of cell organelles. Symbiosis (obligate mutualism) in this lichen is characterized by the harvesting of algal cells by the fungus.

scholarly journals Fine structure of neurosecretory cells and sinus gland in the eyestalk of the freshwater crab Travancoriana schirnerae Bott, 1969 (Decapoda: Gecarcinucidae)

2019 ◽  
Vol 6 (14) ◽  
pp. 535-555
Author(s):  
Sudha Devi Arath Raghavan ◽  
Aswani Ayanath ◽  
Bhadravathi Kenchappa Chandrasekhar Sagar
Keyword(s):  
Fine Structure ◽  
Captive Breeding ◽  
Neurosecretory Cells ◽  
Neurosecretory Material ◽  
Freshwater Crab ◽  
Sinus Gland ◽  
Cell Organelles ◽  
Electron Microscopic ◽  
Lamina Ganglionaris ◽  
Precise Knowledge

This study elucidated the fine structure of neurosecretory cells and sinus gland in the optic ganglia of the freshwater crab Travancoriana schirnerae Bott, 1969 (Decapoda: Gecarcinucidae). The eyestalk ganglion showed the presence of four well defined ganglia arranged below the ommatidium: lamina ganglionaris, medulla externa, medulla interna and medulla terminalis of which the lamina ganglionaris, was devoid of neurosecretory cells. Groups of neurosecretory cells seen distributed along the medulla externa, interna and terminalis regions constitute the X-organs. Electron microscopic observations of the eyestalk ganglia revealed ten types of neurosecretory cells, mostly apolar with a few unipolar and bipolar cells classified according to the size, shape and density of the cell and nucleus, cell organelles/inclusions, together with the arrangement and properties of chromatin. These cells were characterized by the presence of large nuclei with unusually condensed chromatin, inclusions like vacuoles and vesicles of varying size, shape and density and organelles like Golgi, endoplasmic reticulum, ribosomes and mitochondria and neurosecretory material. The sinus gland of T. schirnerae was positioned laterally between the externa and interna regions, composed of axonal endings of the neurosecretory cells of the optic ganglia with interspersed glial cells. The axon terminals were enclosed with several small to large membrane bound homogenously dense neurosecretory granules which also occur in the preterminal areas of the axons. Based on size, shape and density of granules and axoplasmic matrix, seven terminal types could be distinguished in the sinus gland of T. schirnerae. Mostly, the granules contained in a terminal were of the same type; rarely, the same terminal enclosed granules of varying size, shape and density. The neurosecretory cell types and axon terminal types represent the types of neurohormones they contained. A precise knowledge of the morphology and cytology of neurosecretory cells in the XO-SG complex of the eyestalk that secrete neurohormones controlling major physiological processes such as growth and reproduction is imperative for successful captive breeding of a species of aquaculture potential.

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