Ultrastructure of vitellocytes in the cestode Progrillotia pastinacae Dollfus, 1946 (Trypanorhyncha, Progrillotiidae)

2006 ◽  
Vol 51 (3) ◽  
Author(s):  
Zdzisław Świderski ◽  
Jordi Miquel ◽  
Daniel Młocicki ◽  
Lassad Neifar ◽  
Barbara Grytner-Zięcina ◽  
...  
Keyword(s):  
Lipid Droplets ◽  
Saturated Fatty Acids ◽  
Cell Organelles ◽  
Numerous Cell ◽  
Perinuclear Cytoplasm ◽  
Vitelline Cells ◽  
Shell Globule ◽  
Characteristic Features ◽  
Trypanorhynch Cestode ◽  
Mature Vitellocytes

AbstractThe present study describes the ultrastructure of mature vitellocytes of the trypanorhynch cestode Progrillotia pastinacae Dollfus, 1946 (Progrillotiidae), a parasite of the common stingray Dasyatis pastinaca (Linnaeus, 1758) (Dasyatidae). The vitelline cells of this species measure about 24 μm in length and about 20 μm in width. They have small, elongated, slightly lobulated nuclei, about 4–5 μm in length, with large dense elongated nucleoli and numerous irregularly-shaped dense clumps of heterochromatin. The extensive cytoplasm is rich in numerous cell organelles and cell inclusions. While the perinuclear cytoplasm contains numerous long parallel cisternae of GER, ribo-and polyribosomes, several Golgi complexes and mitochondria, the peripheral cytoplasm contains predominantly three types of cell inclusions: a great number of large lipid droplets, several shell globule clusters, and a very small amount of glycogen-like particles. The most characteristic features of vitellocytes in P. pastinacae are having almost no traces of glycogen and the great number of large, highly osmiophobic lipid droplets representing saturated fatty acids. The presence of large amounts of lipids also in two other trypanorhynchs, Grillotia erinaceus (Beneden, 1858) Guiart, 1927 and Dollfusiella spinulifera (Beveridge et Jones, 2000) Beveridge, Neifar et Euzet, 2004, is in strong contrast to the condition in the most evolved cestodes, Cyclophyllidea, that usually show no trace of lipids.

scholarly journals Reinvestigation of vitellogenesis in Caryophyllaeus laticeps (Pallas, 1781) (Cestoda, Caryophyllidea, Caryophyllaeidae), monozoic tapeworm of Abramis brama (Pisces, Teleostei)

2013 ◽  
Vol 50 (1) ◽  
pp. 73-81 ◽  
Author(s):  
M. Bruňanská ◽  
P. Drobníková ◽  
J. Mackiewicz ◽  
J. Nebesářová
Keyword(s):  
Lipid Droplets ◽  
Periodic Acid ◽  
Interstitial Tissue ◽  
Lamellar Bodies ◽  
The Past ◽  
Transmission Electron ◽  
Perinuclear Cytoplasm ◽  
Vitelline Cells ◽  
And Storage ◽  
Mature Vitellocytes

AbstractReinvestigation of vitellogenesis in the caryophyllidean cestode Caryophyllaeus laticeps (Pallas, 1781) has been performed using light microscope (LM) and transmission electron microscopy (TEM), and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) for glycogen. Vitellogenesis is generally similar to that reported in the past, however, some new observations were made. The present study reveals the first evidence of: (i) interstitial tissue in the vitelline follicles, (ii) lipid droplets in maturing and mature vitellocytes from vitelline follicles, and (iii) lamellar bodies in vitellocytes from the vitelloduct in C. laticeps. Projections of interstitial tissue surround each vitellocyte and the follicle periphery. The perinuclear cytoplasm of the interstitial tissue contains granular endoplasmic reticulum and vesicles of various size and density. Cytoplasmic osmiophobic lipid droplets and lamellar bodies, previously believed to be absent in most caryophyllid cestodes, are readily apparent in vitellocytes of C. laticeps. The origin and presumed function of these inclusions are discussed. On the other hand, the formation and storage of massive amounts of glycogen in the nucleus and large amounts in the cytoplasm of mature vitelline cells are similar to the condition found in other caryophyllids. Results are compared and contrasted with previous studies on vitellogenesis in other monopleuroid cestodes (Amphilinidea and Gyrocotylidea) as well as polypleuroid cestodes (Spathebothriidea) and the remaining strobilated Eucestoda.

Fine structure of the vitteline cells in the cestode Proteocephalus longicollis (proteocephalidea)

1978 ◽  
Vol 36 (2) ◽  
pp. 442-443
Author(s):  
Z. Swiderski ◽  
R. D. Eklu-natey ◽  
L. Subilia ◽  
H. Huggel
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Secretory Activity ◽  
Granular Endoplasmic Reticulum ◽  
Secretory Cells ◽  
Cytoplasmic Matrix ◽  
Shell Protein ◽  
Vitelline Cells ◽  
Shell Globule ◽  
Spherical Nuclei

The mature vitelline cells of Proteocephalus longicollis (Zeder, 1800) are ovoid or spherical and measure about 30μm in diameter. They represent the holocrine type of secretory cells.The spherical nuclei, about 10μm in diameter, are localized in the central part of the cell. They contain more or less prominent nucleoli enclosed in the moderately electrondense nucleoplasm (Fig. 1).The cytoplasm (Fig. 2, 3, 4) is packed with numerous shell globules of heterogenous type, large lipid droplets, and a few glycogen islands composed mainly of α-glycogen rosettes.The remaining granular cytoplasmic matrix (Fig. 3, 4) contains: (a) numerous polysomes, (b) cysternae of granular endoplasmic reticulum, (c) several mitochondria, and (d) extended Golgi regions, composed of vesicles of different sizes and density.The extensive development of granular endoplasmic reticulum (GER) and Golgi complexes indicates high secretory activity of these cells. Both Golgi and GER are evidently engaged in shell globule formation and are considered therefore to function as the shell-protein producing units

scholarly journals Ultrastructural and cytochemical study on vitellogenesis in the diphyllidean cestode Echinobothrium euterpes (Echinobothriidae) and its phylogenetical implications

2011 ◽  
Vol 56 (2) ◽  
Author(s):  
Zdzisław Świderski ◽  
John Mackiewicz ◽  
Catarina Eira ◽  
Jordi Miquel
Keyword(s):  
Lipid Droplets ◽  
Plasma Membranes ◽  
Unsaturated Lipid ◽  
Cytochemical Study ◽  
Egg Formation ◽  
Cell Plasma ◽  
Phylogenetic Implications ◽  
Shell Globule ◽  
Glycogen Particles ◽  
Mature Vitellocytes

AbstractThe first description of vitellogenesis in the Diphyllidea is presented in this paper. Though the type of vitellogenesis and mature vitellocyte in Echinobothrium euterpes appear to be unique among the Eucestoda, however, they somewhat resemble that observed in the two orders of the lower cestodes, Tetraphyllidea and Proteocephalidea. Vitellocyte maturation is characterized by: (1) an increase in cell volume; (2) extensive development of short, parallel, frequently concentric cisternae of GER that produce dense proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) progressive formation of saturated lipid droplets; their continuous enlargement and fusion; (5) formation of small accumulations of glycogen particles scattered between and among lipid droplets in the cytoplasm of maturing vitellocytes; (6) concentration of dense proteinaceous granules in the peripheral layer of cytoplasm, around the cell plasma membrane; and (7) vacuolization of cytoplasm of mature vitellocytes accompanied by a rapid increase in its volume. A new, unreported type of dense proteinaceous granules, situated around the limiting plasma membranes of mature vitellocytes, is described. Vitellogenesis evidently differs from that with typical shell-globules and shell-globule clusters previously reported in other taxa of lower cestodes. Cytochemical staining with periodic acidthiosemicarbazide-silver proteinate for glycogen indicates a strongly positive reaction for glycogen particles between and around large unsaturated lipid droplets of the maturing and mature vitellocytes. Some hypotheses concerning the interrelationship between this pattern of vitellogenesis, possible mode of egg formation, embryonic development and diphyllidean life cycle, and their phylogenetic implications are drawn and discussed.

scholarly journals The neuronal endoplasmic reticulum: its cytochemistry and contribution to the endomembrane system. I. Cell bodies and dendrites.

1983 ◽  
Vol 31 (9) ◽  
pp. 1077-1088 ◽  
Author(s):  
R D Broadwell ◽  
A M Cataldo
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Cell Types ◽  
Endomembrane System ◽  
Cell Organelles ◽  
Electron Microscopic ◽  
Enzyme Cytochemistry ◽  
G6pase Activity ◽  
Numerous Cell ◽  
Intracellular Compartments

The endoplasmic reticulum (ER) and its contribution to the endomembrane system (i.e., membranes of cell organelles) in the neuron have been investigated in brains of mice by applying electron microscopic enzyme cytochemistry for demonstration of glucose-6-phosphatase (G6Pase) activity. The phosphohydrolytic activity of G6Pase is a well-known cytochemical marker for the ER in numerous cell types. Of the different substrates employed, glucose-6-phosphate and mannose-6-phosphate were the only two with which G6Pase reaction product was seen in the neuronal ER and organelles related morphologically to the ER. G6Pase activity in cell bodies and dendrites was localized consistently within the lumen of the nuclear envelope, rough and smooth ER, lamellar bodies, hypolemmal and subsurface cisternae, and frequently in the cis saccules of the Golgi apparatus. The G6Pase reactive ER appeared as a network of saccules and tubules pervading the cell body and its dendrites. Possible membrane continuities were identified between the ER and the other reactive structures, including the cis half of the Golgi apparatus. Neither G6Pase activity nor reactive ER was associated with the trans Golgi saccules or GERL. G6Pase activity thus serves as a reliable marker for the perikaryal and dendritic ER and related structures. These observations support the theory that the ER is an integral component of the neuronal endomembrane system associated with the transfer of membrane or membrane molecules among intracellular compartments, the packaging and transport of exportable protein, and energy metabolism. G6Pase activity in the ER of axons and terminals is considered in detail in part two of this study.

Ultrastructural and cytochemical studies on vitellogenesis in trypanorhynch cestode Dollfusiella spinulifera Beveridge, Neifar et Euzet, 2004 (Eutetrarhynchidae)

2006 ◽  
Vol 51 (3) ◽  
Author(s):  
Zdzisław Świderski ◽  
Jordi Miquel ◽  
Daniel Młocicki ◽  
Lassad Neifar ◽  
Barbara Grytner-Zięcina ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Periodic Acid ◽  
Unsaturated Lipids ◽  
Egg Formation ◽  
Large Vesicle ◽  
Cell Plasma ◽  
Shell Globule ◽  
Trypanorhynch Cestode ◽  
Flocculent Material ◽  
Glycogen Particles

AbstractThe first description of vitellogenesis in the Trypanorhyncha is presented in this paper. Though the type of vitellogenesis and mature vitellocyte in Dollfusiella spinulifera appear to be unique among the Eucestoda, to some extent they resemble that observed in the lower cestodes, namely the Tetraphyllidea and Pseudophyllidea. Maturation is characterized by: (1) an increase in cell volume; (2) extensive development of large, parallel, frequently concentric cisternae of GER that produce proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous granules within vesicles and their transformation into shell globule clusters; and (5) progressive fusion of all vesicles, with flocculent material containing the proteinaceous granules and shell globule clusters, into a single very large vesicle that characterises mature vitellocytes of this tapeworm. Cell inclusions in and around the large vesicle consist of flocculent material of a very low density, a few shell globule clusters, moderately dense proteinaceous granules and numerous large droplets of unsaturated lipids. A new previously unreported mode of transformation of proteinaceous granules into shell globule clusters, that evidently differs from that of pseudophyllideans and tetraphyllideans, is described. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for polysaccharides indicates a strongly positive reaction for membrane-bound glycoproteins in all membranous structures such as GER, mitochondria, Golgi complexes, nuclear and cell plasma membranes. Similar staining revealed β-glycogen particles scattered in the cytoplasm of maturing vitellocytes. Typical cytoplasmic β-glycogen particles appear mainly during early vitellocyte maturation but it is characteristic for this species that they are only seldom visible in mature cells. Some working hypotheses concerning the interrelationship between this particular pattern of vitellogensis, possible mode of egg formation in D. spinulifera, its embryonic development and trypanorhynchean life cycle, are drawn and 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.

Effect of different colchicine concentrations on microtubules and membranes in tomato root tip cells

1988 ◽  
Vol 46 ◽  
pp. 306-307
Author(s):  
T.E. Jensen
Keyword(s):  
Plasma Membrane ◽  
Phosphate Buffer ◽  
Cell Types ◽  
Root Tip ◽  
Distilled Water ◽  
Root Tips ◽  
Cell Organelles ◽  
Tomato Root ◽  
Thin Sections ◽  
Numerous Cell

The effect of colchicine on microtubules has been investigated in numerous cell types. In this present study we have used different concentrations of colchicine to determine if the two major groups of microtubules in plant cells, plasma membrane associated and mitotic, are differentially sensitive to this drug.Tomato seeds “Michigan forcing” were germinated on filter paper saturated with distilled water. Radicles 1.5 to 2.0cm were selected and placed into either distilled water or colchicine, 0.001, 0.01, 0.03, 0.04, 0.05, 0.1%, for 20 hrs. During this time they were kept at 20°C in dim light. Root tips were fixed in 3% glutaraldehyde in phosphate buffer at pH7.2 for lh at 4°C. After 5 rinses in buffer they were placed in 1% OsO4 in phosphate buffer at pH7.2 for 1h at 4°C. Root tips were then dehydrated in ethanol, treated with propylene and embedded in Epon.No growth occurred in any of the colchicine treated radicles. Observation of thin sections of control cells revealed many plasma membrane associated microtubules, many cells in division stages and the usual arrangement of cell organelles.

Ultrastructure of the vitellarium in the digeneans Phyllodistomum angulatum (Plagiorchiida, Gorgoderidae) and Azygia lucii (Strigeida, Azygiidae)

2012 ◽  
Vol 57 (3) ◽  
Author(s):  
Larisa Poddubnaya ◽  
Magdaléna Bruňanská ◽  
Zdzisław Świderski ◽  
David Gibson
Keyword(s):  
Lipid Droplets ◽  
Structural Features ◽  
Interstitial Cells ◽  
Surrounding Tissue ◽  
Ultrastructural Studies ◽  
Digenean Species ◽  
Cell Components ◽  
History Of ◽  
Vitelline Cells ◽  
Azygia Lucii

AbstractFine structural features of the vitellarium of two digeneans, Phyllodistomum angulatum and Azygia lucii, are documented and compared with those of other digenean species. The cytodifferentiation of immature vitelline cells (vitellocytes) assumes the production and subsequent accumulation in their cytoplasm of several inclusions. Mature vitelline cells of P. angulatum are characterized by the presence of vitelline clusters (∼2.7 μm in diameter, with ∼100 vitelline globules of ∼0.35 μm in diameter) and osmiophobic, saturated lipid droplets (∼2-3 μm in diameter), and in A. lucii vitelline clusters of the same diameter include much fewer vitelline globules (∼50 globules of ∼0.5 μm in diameter), osmiophilic lipid droplets and α-glycogen. In both P. angulatum and A. lucii, interstitial cells are also present within the vitellarium. Two types of contact sites (septate and tight junctions) between adjoining interstitial cells also occur in both digenean species. Judging from the present and previous ultrastructural studies, it is suggested that there are three potential discriminatory characters of the digenean vitellarium (the number of different types of cell components within the vitellarium, the presence and type of junctional complexes between these cells, and the isolation of the vitellarium from the surrounding tissue) which may prove useful for a better understanding of the biology and evolutionary history of the different digenean groups.

scholarly journals Vitamin B12 Induces Hepatic Fatty Infiltration through Altered Fatty Acid Metabolism

2021 ◽  
Vol 55 (3) ◽  
pp. 241-255
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Vitamin B12 ◽  
Fatty Acid Oxidation ◽  
Lipid Droplets ◽  
De Novo ◽  
Quantitative Polymerase Chain Reaction ◽  
Saturated Fatty Acids ◽  
Fatty Infiltration ◽  
Acid Oxidation

Background/Aims: Rise in global incidence of obesity impacts metabolic health. Evidence from human and animal models show association of vitamin B12 (B12) deficiency with elevated BMI and lipids. Human adipocytes demonstrated dysregulation of lipogenesis by low B12 via hypomethylation and altered microRNAs. It is known de novo hepatic lipogenesis plays a key role towards dyslipidaemia, however, whether low B12 affects hepatic metabolism of lipids is not explored. Methods: HepG2 was cultured in B12-deficient EMEM medium and seeded in different B12 media: 500nM(control), 1000pM(1nM), 100pM and 25pM(low) B12. Lipid droplets were examined by Oil Red O (ORO) staining using microscopy and then quantified by elution assay. Gene expression were assessed with real-time quantitative polymerase chain reaction (qRT-PCR) and intracellular triglycerides were quantified using commercial kit (Abcam, UK) and radiochemical assay. Fatty acid composition was measured by gas chromatography and mitochondrial function by seahorse XF24 flux assay. Results: HepG2 cells in low B12 had more lipid droplets that were intensely stained with ORO compared with control. The total intracellular triglyceride and incorporation of radio-labelled-fatty acid in triglyceride synthesis were increased. Expression of genes regulating fatty acid, triglyceride and cholesterol biosynthesis were upregulated. Absolute concentrations of total fatty acids, saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), trans-fatty acids and individual even-chain and odd-chain fatty acids were significantly increased. Also, low B12 impaired fatty acid oxidation and mitochondrial functional integrity in HepG2 compared with control. Conclusion: Our data provide novel evidence that low B12 increases fatty acid synthesis and levels of individual fatty acids, and decreases fatty acid oxidation and mitochondrial respiration, thus resulting in dysregulation of lipid metabolism in HepG2. This highlights the potential significance of de novo lipogenesis and warrants possible epigenetic mechanisms of low B12.

Formation and disintegration of lipid droplets associated with cell organelles, especially smooth-surfaced endoplasmic reticulum in the white adipose cell

1978 ◽  
Vol 36 (2) ◽  
pp. 260-261
Author(s):  
G. Usuku ◽  
K. Iyama ◽  
K. Ohzono ◽  
M. Hirashima
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Epididymal Adipose Tissue ◽  
Cell Organelles ◽  
Adult Rats ◽  
Adipose Cell ◽  
Ultrastructural Studies ◽  
Functional Relationships ◽  
Lipid Mass ◽  
Electron Microscopical

Although a number of ultrastructural studies on the white adipose cell have been reported, not a few unsolved problems still remain on the morphological and functional relationships between formation or disintegration of lipid droplets and cell organelles in those cells. In order to re-examine such the points, we have made electron microscopical studies on the epididymal adipose cells from normal and starved Wistar adult rats, and on these cells from rats refed ordinary animal food or given only lipid without carbohydrate after a period of starvation. Additionally, for the same purpose we have observed the ultrastructure of developing and differentiating fat cells in the epididymal adipose tissue of rats ranging from newborn to 5 weeks old.The adipose cell from normal adult rats shows that the peripheral cytoplasm which envelopes a central large lipid mass contains well-developed cell organelles and occasionally small lipid droplets. These lipid droplets have no limiting membrane, but are often observed to be closely encircled by fenestrated profiles of smooth-surfaced endoplasmic reticulum (SER) which connects with a part of rough-surfaced endoplasmic reticulum (RER) in places (Fig. 1).

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