scholarly journals The architecture of lipid droplets in the diatom Phaeodactylum tricornutum

2019 ◽  
Vol 38 ◽  
pp. 101415 ◽  
Author(s):  
Josselin Lupette ◽  
Antoine Jaussaud ◽  
Khawla Seddiki ◽  
Christian Morabito ◽  
Sabine Brugière ◽  
...  
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Lipid Droplets

scholarly journals Arginine culture generates triacylglycerol by triggering nitrogen starvation responses during robust growth in Chlamydomonas

2018 ◽  
Author(s):  
Jacob Munz ◽  
Yuan Xiong ◽  
Jaoon Young Hwan Kim ◽  
Young Joon Sung ◽  
Seungbeom Seo ◽  
...  
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Lipid Droplets ◽  
Nitrogen Starvation ◽  
Monounsaturated Fatty Acids ◽  
Growth Impairment ◽  
Lipid Yield ◽  
N Source ◽  
N Starvation ◽  
Induced Genes ◽  
Phototrophic Growth

AbstractUnder nitrogen (N) starvation, microalgae increase carbon storage in the form of lipid droplets while also downregulating photosynthesis and eventually terminating growth. To improve lipid yield, we asked whether lipid droplets and N starvation responses can be induced without limiting growth or photosynthesis. In the chlorophyte Chlamydomonas reinhardtii, gametogenesis is induced either by N starvation or by growth with arginine as the sole N source. We showed that arginine cultures supported robust phototrophic growth, constitutively turned on N starvation-induced genes, and increased lipid droplets. The lipids accumulated in arginine cultures exhibited strong enrichment of saturated and monounsaturated fatty acids, a preferred characteristic of biodiesel precursors. The diatom Phaeodactylum tricornutum also accumulated lipid droplets in arginine culture without growth impairment. We document a system wherein N starvation responses are induced without compromising photosynthesis or growth, thereby suited to the producing valuable chemicals and biofuel precursors without requiring stressors in microalgae.

scholarly journals Stepwise Biogenesis of Subpopulations of Lipid Droplets in Nitrogen Starved Phaeodactylum tricornutum Cells

2020 ◽  
Vol 11 ◽  
Author(s):  
Antoine Jaussaud ◽  
Josselin Lupette ◽  
Juliette Salvaing ◽  
Juliette Jouhet ◽  
Olivier Bastien ◽  
...  
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Lipid Droplets

Ultrastructural Cytopiasmic Changes of Adrenal Cortex During Pregnancy

1969 ◽  
Vol 27 ◽  
pp. 298-299
Author(s):  
T. M. Murad ◽  
Karen Israel ◽  
Jack C. Geer
Keyword(s):  
Adrenal Gland ◽  
Steroid Hormones ◽  
Adrenal Cortex ◽  
Lipid Droplets ◽  
Plasma Cholesterol ◽  
Adrenal Steroids ◽  
Dynamic Changes ◽  
Cortical Cells ◽  
Acetyl Coenzyme A ◽  
Adrenal Cortical Cells

Adrenal steroids are normally synthesized from acetyl coenzyme A via cholesterol. Cholesterol is also shown to enter the adrenal gland and to be localized in the lipid droplets of the adrenal cortical cells. Both pregnenolone and progesterone act as intermediates in the conversion of cholesterol into steroid hormones. During pregnancy an increased level of plasma cholesterol is known to be associated with an increase of the adrenal corticoid and progesterone. The present study is designed to demonstrate whether the adrenal cortical cells show any dynamic changes during pregnancy.

Morphometric SEM study of the effects of ACTH on endothelial fenestrae in the rat adrenal cortex

1984 ◽  
Vol 42 ◽  
pp. 234-235
Author(s):  
J. Curtis ◽  
K. S. Schwartz ◽  
R. P. Apkarian
Keyword(s):  
Anterior Pituitary ◽  
Lipid Droplets ◽  
Adrenocorticotropic Hormone ◽  
Unit Area ◽  
High Density Lipoproteins ◽  
Capillary Endothelium ◽  
Zona Fasciculata ◽  
Sem Study ◽  
Saline Vehicle ◽  
Scanning Electron

A scanning electron microscope (SEM) study was made of the effect of adrenocorticotropic hormone (ACTH) on the size and numbers of fenestrae/unit area in the capillary endothelium of the zona fasciculata (ZF) of the rat adrenal. The stimulatory effect of ACTH on cholesterol uptake via high density lipoproteins in the rat and evidence for the secretion of glucocorticoids by exocytosis of lipid droplets described by Rhodin suggest that endothelial change may accompany these transport phenomena.Twelve rats received two Dexamethasone (DEX) ip injections (25 μg DEX/100 g body wt.), the first at 8 PM and the second at 8 AM the next day, to inhibit the release of endogenous ACTH by the anterior pituitary. The animals were then divided into two groups. Six animals received only saline vehicle and six rats received ACTH (100 ng/100 g body wt.).

Polychlorinated biphenyl induced hepatocyte alterations

1987 ◽  
Vol 45 ◽  
pp. 716-717
Author(s):  
D.N. Collins ◽  
J.N. Turner ◽  
K.O. Brosch ◽  
R.F. Seegal
Keyword(s):  
Lipid Droplets ◽  
Wistar Rats ◽  
Homovanillic Acid ◽  
Polychlorinated Biphenyl ◽  
Corn Oil ◽  
Environmental Pollutants ◽  
Short Term ◽  
Pcb Congeners ◽  
Urinary Levels ◽  
The Brain

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).

An ultrastructural study on the shark liver

1990 ◽  
Vol 48 (3) ◽  
pp. 512-513
Author(s):  
Masako Yamada ◽  
Yutaka Tanuma
Keyword(s):  
Portal Vein ◽  
Kupffer Cells ◽  
Ultrastructural Study ◽  
Lipid Droplets ◽  
Microscopic Level ◽  
The Other ◽  
Fish Stock ◽  
Structural Studies ◽  
Light Microscopic Level ◽  
Perfusion Fixation

Although many fine structural studies on the vertebrate liver have been reported on mammals, avians, reptiles, amphibians, teleosts and cyclostomes, there are no studies on elasmobranchii liver except one by T. Ito etal. (1962) who studied it on light microscopic level. The purpose of the present study was to as certain the ultrastructural details and cytochemical characteristics of normal elasmobranchii liver and was to compare with the other higher vertebrate ones.Seventeen Scyliorhinus torazame, one kind of elasmobranchii, were obtained from the fish stock of the Ueno Zoo aquarium, Ueno, Tokyo. The sharks weighing about 300-600g were anesthetized with MS-222 (Sigma), and the livers were fixed by perfusion fixation via the portal vein according to the procedure of Y. Saito et al. (1980) for 10 min. Then the liver tissues were immersed in the same fixative for 2 hours and postfixed with 1% OsO4-solution in 0.1 Mc acodylate buffer for one hour. In order to make sure a phagocytic activity of Kupffer cells, latex particles (0.8 μm in diameter, 0.05mg/100 g b.w.) were injected through the portal vein for one min before fixation. For preservation of lipid droplets in the cytoplasm, a series of these procedure were performed under ice cold temperature until the end of dehydration.

Where’s the fat? Freeze-fracture analysis of ingredient interactions in food systems

1993 ◽  
Vol 51 ◽  
pp. 48-49
Author(s):  
Jean Fincher
Keyword(s):  
Lipid Droplets ◽  
Food Systems ◽  
Food Industry ◽  
Freeze Fracture ◽  
Food Science ◽  
Complex Interactions ◽  
Fat Reduction ◽  
Important Trend ◽  
Conventional Foods ◽  
Whipped Cream

An important trend in the food industry today is reduction in the amount of fat in manufactured foods. Often fat reduction is accomplished by replacing part of the natural fat with carbohydrates which serve to bind water and increase viscosity. It is in understanding the roles of these two major components of food, fats and carbohydrates, that freeze-fracture is so important. It is well known that conventional fixation procedures are inadequate for many food products, in particular, foods with carbohydrates as a predominant structural feature. For some food science applications the advantages of freeze-fracture preparation procedures include not only the avoidance of chemical fixatives, but also the opportunity to control the temperature of the sample just prior to rapid freezing.In conventional foods freeze-fracture has been used most successfully in analysis of milk and milk products. Milk gels depend on interactions between lipid droplets and proteins. Whipped emulsions, either whipped cream or ice cream, involve complex interactions between lipid, protein, air cell surfaces, and added emulsifiers.

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