120 Effect of bull exposure to high temperature-humidity index levels on the quality of sperm selected through density gradient centrifugation for in vitro fertilisation

2022 ◽  
Vol 34 (2) ◽  
pp. 297
Author(s):  
M. Melean ◽  
C. Herrera ◽  
M. Siuda ◽  
H. Bollwein ◽  
E. Malama
Keyword(s):  
High Temperature ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
In Vitro Fertilisation ◽  
Temperature Humidity Index ◽  
Humidity Index

scholarly journals Identification of storage-protein messenger RNA of the fleshfly Sarcophaga peregrina

1982 ◽  
Vol 203 (3) ◽  
pp. 571-575 ◽  
Author(s):  
T Tahara ◽  
Y Maeda ◽  
A Kuroiwa ◽  
K Ueno ◽  
M Obinata ◽  
...  
Keyword(s):  
Density Gradient ◽  
Storage Protein ◽  
Messenger Rna ◽  
Fat Body ◽  
Density Gradient Centrifugation ◽  
Signal Sequence ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation

Storage-protein mRNA was found to be abundant in poly(A)-containing RNA extracted from the fat-body of third-instar larvae of Sarcophaga peregrina (fleshfly). This RNA sedimented at the position of 19S on sucrose-density-gradient centrifugation and the product of its translation in vitro was 75K protein (protein of mol.wt. 75 000), which was precipitated specifically with antibody against storage protein. This product was suggested to contain a signal sequence that is missing in mature storage protein. The poly(A)-containing RNA was also found to contain much of another mRNA coding for 25K protein (protein of mol.wt. 25 000), but the function of this protein is unknown.

scholarly journals Biosynthesis of proteoglycans in cartilage slices. Fractionation by gel chromatography and equilibrium density-gradient centrifugation

1972 ◽  
Vol 126 (4) ◽  
pp. 791-803 ◽  
Author(s):  
T. E. Hardingham ◽  
Helen Muir
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Guanidine Hydrochloride ◽  
Specific Radioactivity ◽  
Equilibrium Density ◽  
Gel Chromatography ◽  
Sulphate Content

The kinetics of incorporation of [35S]sulphate into slices of pig laryngeal cartilage in vitro was linear with time up to 6h. The specific radioactivities of the extracted proteoglycans (containing about 80% of the uronic acid of the cartilage) and the glycosaminoglycans remaining in the tissue after extraction were measured after various times of continuous and ‘pulse–chase’ radioactivity incorporation. Radioactivity was present in the isolated chondroitin sulphate after 2 min, but there was a 35min delay in its appearance in the extractable proteoglycan fraction. Fractionation of the proteoglycans by gel chromatography showed that the smallest molecules had the highest specific radioactivity, but ‘pulse–chase’ experiments over 5h did not demonstrate any precursor–product relationships between fractions of different size. Equilibrium density-gradient centrifugation in 4m-guanidine hydrochloride showed that among the proteoglycan fractions the specific radioactivity increased as the chondroitin sulphate content decreased, but with preparations from ‘pulse–chase’ experiments there was again no evidence for precursor–product relationships between the different fractions. Differences in radioactive incorporation would seem to reflect metabolic heterogeneity within the proteoglycans extracted from cartilage. This may be due either to a partial separation of different types of proteoglycans or to differences in the rates of degradation of the molecules of different size and composition as a result of the nature and specificity of the normal degrading enzymes. The results suggest that molecules of all sizes were formed at the same time.

ISOLATION OF RAT LEYDIG CELLS BY DENSITY GRADIENT CENTRIFUGATION

1982 ◽  
Vol 92 (2) ◽  
pp. 293-NP ◽  
Author(s):  
J. S. GALE ◽  
J. ST J. WAKEFIELD ◽  
H. C. FORD
Keyword(s):  
Density Gradient ◽  
Binding Sites ◽  
Leydig Cells ◽  
Interstitial Cell ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Collagenase Treatment

A rapid method for preparing Leydig cells from rat testes is described. An interstitial cell suspension, prepared by collagenase treatment of decapsulated testes, was centrifuged for 10 min over a cushion of 60% (v/v) Percoll to remove red blood cells, and then centrifuged for 20 min in a 0–60% linear density gradient of Percoll. Seventy-four per cent of the cells present in that fraction of the gradient comprising 35–50% Percoll were Leydig cells; the yield from each testis was about 1·5 × 106 cells. The Leydig cells appeared viable, excluded Trypan blue, possessed high-affinity binding sites for human chorionic gonadotrophin (hCG) and synthesized increased quantities of testosterone in response to hCG. The cells could be stored overnight in 20% (v/v) glycerol at −20 °C, with only minimal effect on the specific activities of a number of enzymes used as markers of subcellular components. Testosterone production in vitro by the cells after storage for 20 h was greater than that of hCG-stimulated fresh cells and was not further increased by hCG.

Further evidence for the presence of androgen receptors in the lungs and in the head appendages of the cock

1977 ◽  
Vol 55 (3) ◽  
pp. 263-265 ◽  
Author(s):  
Jean Y. Dubé ◽  
Pierre Chapdelaine ◽  
Roland R. Tremblay
Keyword(s):  
Density Gradient ◽  
Mechanism Of Action ◽  
Androgen Receptors ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
In Vitro Binding ◽  
Vitro Binding

The presence of cytoplasmic dihydrotestosterone receptors in the lungs, the comb, the wattle, and the ear lobes of the cock was demonstrated by sucrose density-gradient centrifugation. All these tissues exhibited saturable 'in vitro' binding of dihydrotestosterone in the 8–11S region of the gradient. When 0.5 M KCl was added to the lung, wattle, and comb cytosols and to the gradients, the radioactive dihydrotestosterone migrated in the 4–5S region. These studies suggest that the mechanism of action of androgens in the head appendages of the cock and in other target tissues is similar.

Study of tobacco mosaic virus in vitro disassembly by sucrose density gradient centrifugation and agarose gel electrophoresis

1984 ◽  
Vol 62 (3) ◽  
pp. 457-462 ◽  
Author(s):  
Richard Hogue ◽  
Alain Asselin
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Density Gradient ◽  
Gel Electrophoresis ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Agarose Gel ◽  
Agarose Gel Electrophoresis ◽  
Sucrose Density Gradient Centrifugation

In vitro disassembly of tobacco mosaic virus (TMV) strains U1, U2, U4, U6, and U7 with alkali and urea was studied by sucrose or sucrose–dimethylsulfoxide (DMSO) density gradient centrifugation and by agarose gel electrophoresis. All strains gave similar decapsidation patterns with both agents when partially stripped virus particles (PSVs) were analyzed by sedimentation and electrophoresis. However, U6 was more sensitive to decapsidation than the other strains and U2 exhibited resistance to decapsidation. Agarose gel electrophoresis of TMV decapsidation products allowed the detection of several classes of PSVs in addition to aggregation products involving PSVs and monomer particles. Agarose gel electrophoresis is thus very rapid and useful for analysis of TMV disassembly products especially when aggregation phenomena and kinetic studies with numerous samples are considered.

scholarly journals Lysosomes, but not mitochondria, accumulate iron and porphyrins in porphyria induced by hexachlorobenzene

1986 ◽  
Vol 235 (3) ◽  
pp. 671-675 ◽  
Author(s):  
A Tangerås
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Iron Status ◽  
Gradient Centrifugation ◽  
Female Rats ◽  
Percoll Density Gradient Centrifugation ◽  
Mitochondrial Fractions ◽  
Percoll Density Gradient ◽  
Haem Iron

In female rats with porphyria induced by hexachlorobenzene, the amounts of non-haem iron and porphyrins in liver mitochondrial fractions were increased almost 3-fold and greater than 500-fold respectively compared with that of untreated animals. A considerable fraction of both iron and porphyrins in this fraction was shown to be located in lysosomes. Thus mitochondrial preparations, which were further depleted of lysosomes by Percoll-density-gradient centrifugation, contained 2.78 +/- 0.75 and 2.99 +/- 0.49 nmol of non-haem iron/mg of protein when isolated from the liver of control rats and hexachlorobenzene-treated rats respectively. Mitochondria isolated from the liver of hexachlorobenzene-treated animals contained a pool of iron (about 1 nmol/mg of protein) that was available for haem synthesis in vitro. This pool is similar to that previously reported for mitochondria isolated from the liver of rats with normal haem synthesis. Hexachlorobenzene treatment, therefore, does not affect the iron status of the mitochondria.

The polypeptide components of scintillons, the bioluminescence organelles of the dinoflagellate Gonyaulax polyedra

1993 ◽  
Vol 71 (3-4) ◽  
pp. 176-182 ◽  
Author(s):  
Michel Desjardins ◽  
David Morse
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Binding Protein ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Close Packing ◽  
Gonyaulax Polyedra

Scintillons, the bioluminescence organelles of Gonyaulax polyedra, were purified by isopycnic density gradient centrifugation until only low levels of contaminating chloroplasts and mitochondria were detected by fluorescence and electron microscopy. Purified scintillons catalyzed the luminescent reaction with kinetics identical to those observed during the bioluminescence flash in vivo. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate indicated that the organelles appeared to contain only two proteins. These proteins were identified as luciferase (135 kilodaltons) and luciferin-binding protein (75 kilodaltons) based on their size and their known functions in the bioluminescence reaction in vitro. The staining of luciferin-binding protein by Coomassie blue was 2.4 ± 0.3 (n = 19) times greater than the luciferase, suggesting that there are four binding protein monomers for every luciferase monomer. A model is proposed for the close packing of the two proteins inside the scintillons.Key words: luciferase, luciferin-binding protein, density gradient centrifugation, dinoflagellate.

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