Ultrastructure of laticifers in seedlings of Glaucium flavum (Papaveraceae)

1982 ◽  
Vol 60 (5) ◽  
pp. 561-567 ◽  
Author(s):  
Craig L. Nessler
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Cell Differentiation ◽  
Wall Material ◽  
Starch Grains ◽  
Perforation Site ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Unknown Composition

Laticifers in seedlings of Glaucium flavum Crantz were examined by electron microscopy. Laticifer initials first apeared in procambium of the radicle adjacent to the phloem about 48–72 h after germination. Differentiation of laticifer initials was characterized by the proliferation of numerous vesicles from dilation of endoplasmic reticulum. The usual complement of organelles was present in laticifer elements including a nucleus, mitochondria, dictyosomes, and plastids. Plastids were devoid of organized lamellae and starch grains but contained electron-dense, membrane-bound inclusions. Large crystalline bodies of unknown composition were also seen in the cytoplasm of some laticifer elements. Perforations were not observed in the longitudinal walls shared by adjacent laticifer elements; thus the laticifer system in this species can be classified as nonanastomosing. Transverse walls between laticifer elements remained intact until late in cell differentiation; however, large perforations did form in these walls as a result of the gradual removal of wall material at the perforation site.

scholarly journals The Fine Structure of the Wheat Scutellum During Germination

1972 ◽  
Vol 25 (3) ◽  
pp. 469 ◽  
Author(s):  
JG Swift ◽  
TP O'brien
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Wall Material ◽  
Cytological Evidence ◽  
Starch Grains ◽  
Parenchyma Cells ◽  
Cytological Changes

The cytological changes that take place in the scutellar epithelium and parenchyma during the first 5 days of germination are described by light and electron microscopy. Within 6 hr small starch grains appear in the plastids of both cell types and the size and number of starch grains increase gradually as germination proceeds. Later in germination starch disappears again from the plastids in the epithelial cells, but large starch grains still remain in the parenchyma cells. The reserves of the protein bodies are hydrolysed and the residual vacuoles undergo extensive coales-cence. Modifications in the appearance of the wall material of the epithelial cells as these cells elongate are illustrated and possible functional bases for these changes are suggested. The cells of the scutellar epithelium show no cytological evidence for their known functions of diastase secretion and nutrient absorption.

Evidence for Golgi Origin of Melanosomes

1968 ◽  
Vol 26 ◽  
pp. 148-149
Author(s):  
Gerd G. Maul
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Golgi Complex ◽  
Serial Sections ◽  
Human Malignant Melanoma ◽  
Close Proximity ◽  
Membrane Bound ◽  
Tubular Endoplasmic Reticulum ◽  
Internal Architecture

Electron microscopy has provided evidence that the melanosome evolves as a membrane bound structure with a highly complex internal architecture. The premelanosomes are found in close proximity to the golgi apparatus. Therefore, it was generally agreed that the melanosomes originate from the golgi apparatus.Vesicles have been described to pinch off the cysternae of the golgi apparatus. The vesicles would then grow and acquire a dense material. This material is aggregating to form the characteristic helical strands onto which melanin is deposited. Cloned human malignant melanoma lines were used to reinvestigate the problem of melanosome formation. The reconstruction of serial sections revealed the arrangement of premelanosomes and melanosomes in relation to the golgi complex. This study demonstrated that premelanosomes and melanosomes are continuous with the golgi complex by a smooth-surfaced tubular endoplasmic reticulum (SER) (Fig. la-d). The continuity of membranes of the SER and the premelanosome is depicted in Fig. 2. In this early premelanosome the protein strands have not yet coiled up into a helix. Rough-surfaced endoplasmic reticulum (RER) was also observed to be continuous with the golgi apparatus and melanosomes. After melanogenesis has started (Fig. 3) small vesicles appear inside the premelanosomes.

scholarly journals FINE STRUCTURE OBSERVATIONS OF THE UPTAKE OF INTRAVENOUSLY INJECTED PEROXIDASE BY THE RAT CHOROID PLEXUS

1967 ◽  
Vol 15 (3) ◽  
pp. 160-165 ◽  
Author(s):  
NORWIN H. BECKER ◽  
ALEX B. NOVIKOFF ◽  
H. M. ZIMMERMAN
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Cerebrospinal Fluid ◽  
Choroid Plexus ◽  
Smooth Endoplasmic Reticulum ◽  
Multivesicular Bodies ◽  
Adult Rats ◽  
Dense Bodies ◽  
Pinocytotic Vesicles ◽  
Membrane Bound

The uptake by the choroid plexus of adult rats of intravenously injected horseradish peroxidase has been investigated by electron microscopy. Within 4 min, the injected protein passes the capillary and is rapidly distributed through extracellular space and choroidal cells. Peroxidase enters the choroidal cells within coated vesicles which act as pinocytotic vesicles. At 15 min, peroxidase activity is present in numerous membrane-bound vesicles, multivesicular bodies, dense bodies and what appear to be segments of smooth endoplasmic reticulum. None of the peroxidase-containing organelles is seen to empty to the ventricular surface. Egress of the extracellular peroxidase into the cerebrospinal fluid is apparently blocked by apical zonulae occludentes between the choroidal cells.

Localization of various phosphatase activities within the golgi apparatus and lysosomes of rat leydig cells

1986 ◽  
Vol 44 ◽  
pp. 294-295
Author(s):  
M. F. Lalli ◽  
V. Lacroix ◽  
L. Hermo ◽  
Y. Clermont ◽  
C. E. Smith
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Leydig Cells ◽  
Smooth Endoplasmic Reticulum ◽  
Fluid Phase ◽  
Multivesicular Bodies ◽  
Golgi Stack ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Adsorptive Endocytosis

The testosterone-secreting Leydig cells contain an abundance of smooth endoplasmic reticulum, peroxisomes, mitochondria as well as a large, spheroidal, juxtanuclear Golgi apparatus composed of interconnected stacks of saccules (Figs. 1,2). Each Golgi stack appears to be composed of between 5 to 7 saccules or sacculo-tubular elements (Figs.1,2). These cells also possess pale and dense multivesicular bodies and dense membrane-bound bodies identified assecondary lysosomes, all of which have been shown to be involved in fluid phase and adsorptive endocytosis as well as in receptor mediated endocytosis. The purpose of the present study was to characterize the reactivity of Golgi saccules, multivesicular bodies and lysosomes of Leydig cells for different phosphatases.

Electron microscopy of the conidial protoplasts of Neurospova crassa

1968 ◽  
Vol 46 (12) ◽  
pp. 1561-1564 ◽  
Author(s):  
M. S. Manocha
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Conidial Germination ◽  
Cell Wall Structure ◽  
Wall Material ◽  
Wall Structure ◽  
Protoplast Formation ◽  
Small Pore ◽  
Similarities And Differences

Micromorphology of conidia resembles that of young hyphae except for the details of the cell wall structure, which is thicker and prominently developed in unhydrated conidia. Although mitochondria and endoplasmic reticulum are present in ungerminated conidia, these organelles increase greatly during germination, and vacuoles increase in size and number. Naked protoplasts protrude through a small pore in the partially digested wall of the conidium. Free protoplasts synthesize new wall material when incubated in a regenerative mixture. Similarities and differences between conidial germination and protoplast formation and regeneration are noted.

Ultrastructure of dormant basidiospores of Agaricus campestris

1988 ◽  
Vol 66 (3) ◽  
pp. 583-587 ◽  
Author(s):  
Donald G. Ruch ◽  
Mary C. North
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Short Distance ◽  
Mitochondrial Membrane ◽  
Lipid Droplets ◽  
Wall Material ◽  
Outer Mitochondrial Membrane ◽  
The Third ◽  
Membrane Bound ◽  
Agaricus Campestris

The basidiospore wall of Agaricus campestris Fr. consists of three distinct layers. The outer two layers are continuous around the spore, while the third layer originates only a short distance from the hilar appendage and quickly thickens to form the bulk of the wall material of the hilar appendage. The protoplast is surrounded by a typical plasma membrane which lacks distinct invaginations. Centrally located nonmembrane-bound lipid droplets comprise the bulk of the protoplasm. Spores are binucleate, but the two nuclei do not exhibit any distinct relationship to each other. Sausage-shaped mitochondria with only a few but well-delineated plate-like cristae are present. Scant endoplasmic reticulum occurs just beneath the plasma membrane. Ribosomes occur regularly attached to the endoplasmic reticulum and outer mitochondrial membrane, as well as being densely packed throughout the cytoplasm. The structure and possible functions of single membrane bound vacuoles and microbody-like organelles are discussed in relation to other basidiospores.

Cytology of mucilage production in the seed coat of Candle canola (Brassica campestris)

1981 ◽  
Vol 59 (3) ◽  
pp. 292-300 ◽  
Author(s):  
L. Van Caeseele ◽  
J. T. Mills ◽  
M. Sumner ◽  
R. Gillespie
Keyword(s):  
Electron Microscopy ◽  
Seed Coat ◽  
Brassica Campestris ◽  
Light And Electron Microscopy ◽  
Epidermal Cells ◽  
Starch Grains ◽  
Golgi Bodies ◽  
Tangential Wall ◽  
Membrane Bound

The development of mucilage in the epidermal cells of canola seeds (Brassica campestris L. cv. Candle) was studied with light and electron microscopy from 5 days after pollination to maturity. During the first 17 days starch was deposited in amyloplasts. At or near the 17th day mucilage appeared between the plasmalemma and the outer tangential wall of the epidermal cells. As the volume of mucilage increased, starch grains disappeared and were totally absent by 25 days. Membrane-bound structures and Golgi bodies were visible within the cytoplasm adjacent to the site of mucilage deposition. At maturity the seed epidermal cells were totally devoid of cytoplasm and engorged with mucilage.

Modification of Pineal Ultrastructure by Exogenous Hormones

1967 ◽  
Vol 25 ◽  
pp. 170-171
Author(s):  
R. A. Turner ◽  
A. E. Rodin ◽  
D. K. Roberts
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
List Type ◽  
Type Number ◽  
Pregnant Rats ◽  
Gonadal Atrophy ◽  
Pineal Ultrastructure

There have been many reports which establish a relationship between the pineal and sexual structures, including gonadal hypertrophy after pinealectomy, and gonadal atrophy after injection of pineal homogenates or of melatonin. In order to further delineate this relationship the pineals from 5 groups of female rats were studied by electron microscopy:ControlsPregnant ratsAfter 4 weekly injections of 0.1 mg. estradiol benzoate.After 8 daily injections of 150 mcgm. melatonin (pineal hormone).After 8 daily injections of 3 mg. serotonin (melatonin precursor).No ultrastructural differences were evident between the control, and the pregnancy and melatonin groups. However, the estradiol injected animals exhibited a marked increase in the amount and size of rough endoplasmic reticulum within the pineal cells.

Copper Localization in Cirrhotic Rat Liver by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 38-39 ◽  
Author(s):  
J. C. Russ ◽  
E. McNatt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Copper Acetate ◽  
Lead Citrate ◽  
Dense Bodies ◽  
Transmission Electron ◽  
Electron Mode ◽  
Scanning Electron

In order to study the retention of copper in cirrhotic liver, rats were made cirrhotic by carbon tetrachloride inhalation twice weekly for three months and fed 0.2% copper acetate ad libidum in drinking water for one month. The liver tissue was fixed in osmium, sectioned approximately 2000 Å thick, and stained with lead citrate. The section was examined in a scanning electron microscope (JEOLCO JSM-2) in the transmission electron mode.Figure 1 shows a typical area that includes a red blood cell in a sinusoid, a disse, and a portion of the cytoplasm of a hepatocyte which contains several mitochondria, peribiliary dense bodies, glycogen granules, and endoplasmic reticulum.

Analysis of the Anterior Secretory Cells of Onchidohs Muricata (Nudibranchia)

1981 ◽  
Vol 39 ◽  
pp. 614-615
Author(s):  
Roy Skidmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Golgi Body ◽  
The Body ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
High Magnification ◽  
Large Numbers ◽  
Membrane Bound ◽  
Sole Of The Foot

The long-necked secretory cells in Onchidoris muricata are distributed in the anterior sole of the foot. These cells are interspersed among ciliated columnar and conical cells as well as short-necked secretory gland cells. The long-necked cells contribute a significant amount of mucoid materials to the slime on which the nudibranch travels. The body of these cells is found in the subepidermal tissues. A long process extends across the basal lamina and in between cells of the epidermis to the surface of the foot. The secretory granules travel along the process and their contents are expelled by exocytosis at the foot surface.The contents of the cell body include the nucleus, some endoplasmic reticulum, and an extensive Golgi body with large numbers of secretory vesicles (Fig. 1). The secretory vesicles are membrane bound and contain a fibrillar matrix. At high magnification the similarity of the contents in the Golgi saccules and the secretory vesicles becomes apparent (Fig. 2).

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