scholarly journals Storage products and tissue interaction in the ovule of Pinus silvestris (L.)

2014 ◽  
Vol 50 (1-2) ◽  
pp. 339-344 ◽  
Author(s):  
F. M. Engels
Keyword(s):  
Low Temperatures ◽  
Lipid Synthesis ◽  
Lipid Storage ◽  
Pinus Silvestris ◽  
Ovule Development ◽  
Tissue Interaction ◽  
Storage Products ◽  
Plug Formation

The organel-sequence in ovular cells of <em>Pinus silvestris</em> was investigated by light- and electronmicroscopy during the post-pollination and pre-fertilization period. Changes in starch and lipid storage suppose starch to be a pool for lipid synthesis and a reserve for ovule development. The base nucellus plays an important role in the distribution of metabolites all over the ovular tissues. Lipid, starch and callose are of interest for the cells to protect them against low temperatures by means of isolation, antifreeze and plug formation respectively.

scholarly journals Genome-Wide Analysis of Sterol-Lipid Storage and Trafficking in Saccharomyces cerevisiae

2007 ◽  
Vol 7 (2) ◽  
pp. 401-414 ◽  
Author(s):  
Weihua Fei ◽  
Gabriel Alfaro ◽  
Baby-Periyanayaki Muthusamy ◽  
Zachary Klaassen ◽  
Todd R. Graham ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Neutral Lipid ◽  
Lipid Synthesis ◽  
Secretory Protein ◽  
Lipid Storage ◽  
Protein Glycosylation ◽  
Particle Assembly ◽  
Genome Wide ◽  
And Storage

ABSTRACT The pandemic of lipid-related disease necessitates a determination of how cholesterol and other lipids are transported and stored within cells. The first step in this determination is the identification of the genes involved in these transport and storage processes. Using genome-wide screens, we identified 56 yeast (Saccharomyces cerevisiae) genes involved in sterol-lipid biosynthesis, intracellular trafficking, and/or neutral-lipid storage. Direct biochemical and cytological examination of mutant cells revealed an unanticipated link between secretory protein glycosylation and triacylglycerol (TAG)/steryl ester (SE) synthesis for the storage of lipids. Together with the analysis of other deletion mutants, these results suggested at least two distinct events for the biogenesis of lipid storage particles: a step affecting neutral-lipid synthesis, generating the lipid core of storage particles, and another step for particle assembly. In addition to the lipid storage mutants, we identified mutations that affect the localization of unesterified sterols, which are normally concentrated in the plasma membrane. These findings implicated phospholipase C and the protein phosphatase Ptc1p in the regulation of sterol distribution within cells. This study identified novel sterol-related genes that define several distinct processes maintaining sterol homeostasis.

Nile red as a probe for lipid-storage products in benthic copepods

1991 ◽  
Vol 75 ◽  
pp. 307-311
Author(s):  
KR Carman ◽  
D Thistle ◽  
SC Ertman ◽  
M Foy
Keyword(s):  
Nile Red ◽  
Lipid Storage ◽  
Storage Products

Factors affecting seed set in Douglas-fir (Pseudotsuga menziesii)

1991 ◽  
Vol 69 (2) ◽  
pp. 229-238 ◽  
Author(s):  
John N. Owens ◽  
Anna M. Colangeli ◽  
Sheila J. Morris
Keyword(s):  
Reproductive Success ◽  
Pseudotsuga Menziesii ◽  
Low Temperatures ◽  
Seed Set ◽  
Douglas Fir ◽  
Ovule Development ◽  
High Moisture ◽  
Embryo Abortion ◽  
Factors Affecting ◽  
Major Loss

Cone and seed development in Douglas-fir were studied from pollination until seed release in 1986. Cone abortion at, and shortly after, pollination was high, resulting from a combination of low temperatures and possibly high moisture and populations of microorganisms on cones. Seed potential averaged about 75 seeds per cone with 31 filled seed per cone, giving an average seed efficiency of 39%. The major loss of seed resulted from insufficient pollen in the ovules. Other causes were ovule and embryo abortion at various stages of development. The effects of prezygotic and postzygotic events on seed set are discussed with respect to the reproductive success of Douglas-fir. Key words: Douglas-fir, seed set, cone, ovule, development, abortion.

scholarly journals Nile red as a probe for lipid-storage products in benthic copepods

1991 ◽  
Vol 74 ◽  
pp. 307-311 ◽  
Author(s):  
KR Carman ◽  
D Thistle ◽  
SC Ertman ◽  
M Foy
Keyword(s):  
Nile Red ◽  
Lipid Storage ◽  
Storage Products

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

The diagnosis of metabolic storage disease in skin biopsies (a light-, electronmicroscopic, and analytical study)

1978 ◽  
Vol 36 (2) ◽  
pp. 648-649
Author(s):  
W. Jurecka ◽  
W. Gebhart ◽  
H. Lassmann
Keyword(s):  
Storage Disease ◽  
Hunter Syndrome ◽  
Histochemical Demonstration ◽  
Sweat Glands ◽  
Type I ◽  
Storage Material ◽  
Scheie Syndrome ◽  
Storage Products ◽  
Skin Biopsies ◽  
Type V

Diagnosis of metabolic storage disease can be established by the determination of enzymes or storage material in blood, urine, or several tissues or by clinical parameters. Identification of the accumulated storage products is possible by biochemical analysis of isolated material, by histochemical demonstration in sections, or by ultrastructural demonstration of typical inclusion bodies. In order to determine the significance of such inclusions in human skin biopsies several types of metabolic storage disease were investigated. The following results were obtained.In MPS type I (Pfaundler-Hurler-Syndrome), type II (Hunter-Syndrome), and type V (Ullrich-Scheie-Syndrome) mainly “empty” vacuoles were found in skin fibroblasts, in Schwann cells, keratinocytes and macrophages (Dorfmann and Matalon 1972). In addition, prominent vacuolisation was found in eccrine sweat glands. The storage material could be preserved in part by fixation with cetylpyridiniumchloride and was also present within fibroblasts grown in tissue culture.

Cytoplasmic Granules in Lymphocytes from Rats Dosed with SK&F 14336-D

1971 ◽  
Vol 29 ◽  
pp. 556-557
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis
Keyword(s):  
Lipid Storage ◽  
Pokeweed Mitogen ◽  
Electron Microscopic ◽  
Cytoplasmic Granules ◽  
Storage Diseases ◽  
Tay Sachs Disease ◽  
Large Numbers ◽  
Microscopic Studies ◽  
Neurovisceral Lipidosis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.

Interpretation of irradiation-induced changes in electron diffractograms and images of extinction contours at low temperatures

1984 ◽  
Vol 42 ◽  
pp. 268-269
Author(s):  
E. Knapek ◽  
H. Formanek ◽  
G. Lefranc ◽  
I. Dietrich
Keyword(s):  
Low Temperatures ◽  
Carbon Films ◽  
Organic Crystals ◽  
Wide Spread ◽  
Lens System ◽  
Preparation Conditions ◽  
Thin Carbon ◽  
Electron Diffractograms ◽  
Diffraction Patterns ◽  
Induced Changes

A few years ago results on cryoprotection of L-valine were reported, where the values of the critical fluence De i.e, the electron exposure which decreases the intensity of the diffraction reflections by a factor e, amounted to the order of 2000 + 1000 e/nm2. In the meantime a discrepancy arose, since several groups published De values between 100 e/nm2 and 1200 e/nm2 /1 - 4/. This disagreement and particularly the wide spread of the results induced us to investigate more thoroughly the behaviour of organic crystals at very low temperatures during electron irradiation.For this purpose large L-valine crystals with homogenuous thickness were deposited on holey carbon films, thin carbon films or Au-coated holey carbon films. These specimens were cooled down to nearly liquid helium temperature in an electron microscope with a superconducting lens system and irradiated with 200 keU-electrons. The progress of radiation damage under different preparation conditions has been observed with series of electron diffraction patterns and direct images of extinction contours.

Radiation Damage of Support Films

1981 ◽  
Vol 39 ◽  
pp. 28-29
Author(s):  
H.A. Cohen ◽  
W. Chiu
Keyword(s):  
Transfer Function ◽  
Low Temperatures ◽  
Carbon Support ◽  
Contrast Transfer Function ◽  
Electron Dose ◽  
Imaging Parameters ◽  
Negative Stain ◽  
Phase Corrections ◽  
Two Parameters ◽  
Medium Dose

The goal of imaging the finest detail possible in biological specimens leads to contradictory requirements for the choice of an electron dose. The dose should be as low as possible to minimize object damage, yet as high as possible to optimize image statistics. For specimens that are protected by low temperatures or for which the low resolution associated with negative stain is acceptable, the first condition may be partially relaxed, allowing the use of (for example) 6 to 10 e/Å2. However, this medium dose is marginal for obtaining the contrast transfer function (CTF) of the microscope, which is necessary to allow phase corrections to the image. We have explored two parameters that affect the CTF under medium dose conditions.Figure 1 displays the CTF for carbon (C, row 1) and triafol plus carbon (T+C, row 2). For any column, the images to which the CTF correspond were from a carbon covered hole (C) and the adjacent triafol plus carbon support film (T+C), both recorded on the same micrograph; therefore the imaging parameters of defocus, illumination angle, and electron statistics were identical.

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