Yolk Protein Synthesis in the Ovary of Octopus Vulgaris and its Control by the Optic Gland Gonadotropin

1973 ◽  
Vol 59 (3) ◽  
pp. 665-674
Author(s):  
R. K. O'DOR ◽  
M. J. WELLS
Keyword(s):  
Protein Synthesis ◽  
High Rate ◽  
Follicle Cells ◽  
Blood Protein ◽  
Octopus Vulgaris ◽  
Yolk Proteins ◽  
Stage Of Development ◽  
Rapid Accumulation ◽  
A Site

1. Over 98% of a dose of [14C]leucine injected into the circulation of Octopus vulgaris is removed from the blood during the first hour. 2. There is a rapid accumulation of labelled protein in the ovaries of maturing animals within 2 h of injection. Within 5-7 h the ovaries contain nearly 40% of the injected label in protein form. 3. Removal of the optic glands prevents this accumulation of protein. 4. There is little labelled protein in the livers of either control or maturing animals at any time; but a slow, steady accumulation occurs in their blood. 5. The level of labelled protein appearing in the blood of acutely ovariectomized, maturing females is no higher than in controls; and when blood protein from ovariectomized animals is injected into normal maturing females it is not taken up by the ovaries. 6. The labelled protein which accumulates in the blood is probably haemocyanin. Preliminary experiments indicate that the branchial glands, which are already believed to be a site of haemocyanin synthesis on morphological grounds, show a high rate of protein synthesis and release. 7. Isolated ovarian follicles in a liquid medium synthesize protein at a rate somewhat lower, but comparable with, the apparent in vivo rate. 8. The combined evidence from these experiments indicates that in Octopus yolk proteins are formed within the ovary-probably by the follicle cells-rather than being synthesized elsewhere and transported through the blood, as in arthropods and vertebrates. 9. The optic gland gonadotropin is essential for maintenance of protein synthesis during secondary vitellogenesis and the follicle cells are a likely site for its action during this stage of development.

An in vitro bioassay for a mulluscan gonadotropin

1975 ◽  
Vol 62 (2) ◽  
pp. 433-446
Author(s):  
M. J. Wells ◽  
R. K. O'Dor ◽  
S. K. Buckley
Keyword(s):  
Protein Synthesis ◽  
High Rate ◽  
Follicle Cells ◽  
Octopus Vulgaris ◽  
Amino Acid Incorporation ◽  
Gland Extract ◽  
Acid Incorporation ◽  
Kinetics Of

1. Protein synthesis occurs at a high rate in the ovaries of maturing Octopus vulgaris and can be measured from the incorporation of [14C]leucine in vivo and in isolated groups of eggs in vitro. 2. Removal of the optic glands in vivo 1--3 days prior to testing markedly reduces amino acid incorporation in vivo or in vitro. After 5 days in vivo incorporation stops. 3. The rate of incorporation in vitro is increased by the addition of optic gland extract. 4. Analysis of the kinetics of leucine uptake and incorporation in vitro indicates that the hormone has an effect on the inward transport of leucine which is independent of its action on protein synthesis. 5. Electron-microscope studies of the follicle cells and ova show that the former are the site of protein synthesis. 6. Changes in either uptake or incorporation into protein by the follicle cells can be used as a qualitative biolobical assay for the optic gland hormone. Uptake is very easy to measure but incorporation is the more sensitive parameter. Either is potentially suitable as a quantitative assay for this and perhaps also for other molluscan gonadotropins.

Changes in protein synthesis during the development of Xenopus laevis

Development ◽  
1979 ◽  
Vol 51 (1) ◽  
pp. 137-153
Author(s):  
J. E. M. Ballantine ◽  
H. R. Woodland ◽  
E. A. Sturgess
Keyword(s):  
Protein Synthesis ◽  
Translational Control ◽  
Gene Activity ◽  
Specific Gene ◽  
Two Dimensional Gel Electrophoresis ◽  
Free System ◽  
Stage Of Development ◽  
New Gene ◽  
Made In

Patterns of protein synthesis during the development of Xenopus were studied by two-dimensional gel electrophoresis. Up to the end of the blastula stage we find no newly synthesized proteins which are not already made in the oocyte. The first new proteins are seen during gastrulation, and they increase in number during neurulation. Some of these are restricted to the ‘ectodermal’ region, and some to the ‘endodermal’ region of embryos divided into two parts. These new, region-specific proteins include α-actin. When the oocyte matures the number of detectable newly synthesized proteins decreases, reaching a minimum in the unfertilized egg. Some, such as β- and γ-actin, re-appear at the end of cleavage. This could not be shown to be a recovery artifact. The relation of the total mRNA to these changes in protein synthesis was studied by translation in the lysed reticulocyte cell-free system. The mRNAs that code for oocyte proteins that cease synthesis in the unfertilized egg and re-appear in blastulae are nevertheless detectable in total RNA made from eggs. These proteins therefore seem to cease and resume synthesis through translational control. mRNAs for new proteins first appear after gastrulation, just when these proteins are first detected in vivo. This strongly suggests, though it does not prove, that new gene activity is involved. It is therefore likely that region-specific gene activity is already present by the gastrula stage of development, and has an impact on the most abundant kinds of proteins made in the embryo.

Peroxidase biosynthesis as part of protein synthesis by cultured peanut cells

1980 ◽  
Vol 58 (9) ◽  
pp. 715-719 ◽  
Author(s):  
D. Stephan ◽  
R. B. Van Huystee
Keyword(s):  
Molecular Weight ◽  
Protein Synthesis ◽  
Wheat Germ ◽  
High Rate ◽  
Secreted Protein ◽  
Radioactive Product ◽  
Significant Information ◽  
Membrane Bound

Membrane-bound and free ribosomes from cultured peanut cells were separated by differential centrifugation. The former ribosomes were liberated from the 27 000 × g pellet with 1% Triton X100. Purification of both polysome populations was obtained by passage through a 1.5 M sucrose cushion. Both populations have a high rate of protein synthesis in vitro in the presence of a wheat germ S30 fraction. Comparisons of protein synthesis in vitro with that in vivo, and also with labelled proteins released by these cells into the medium did not provide significant information regarding peroxidase biosynthesis. However, immunoprecipitation of the products formed in vitro with antibodies raised against a purified cationic peroxidase fraction, resulted in isolating one major radioactive product. The higher molecular weight of this isolated product compared with the molecular weight of the purified peroxidase fraction suggests the occurrence of a signal peptide for peroxidase commensurate with its being a secreted protein.

Respiratory energy requirements and rate of protein turnover in vivo determined by the use of an inhibitor of protein synthesis and a probe to assess its effect

1994 ◽  
Vol 92 (4) ◽  
pp. 585-594 ◽  
Author(s):  
T. J. Bouma ◽  
R. De Visser ◽  
J. H. J. A. Janssen ◽  
M. J. De Kock ◽  
P H. Van Leeuwen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Energy Requirements ◽  
Inhibitor Of Protein Synthesis

A view at the Russian economic transformation

2018 ◽  
pp. 142-158 ◽  
Author(s):  
E. F. Baranov ◽  
V. A. Bessonov
Keyword(s):  
Market Economy ◽  
Growth Rates ◽  
Transition Process ◽  
Well Being ◽  
Economic Transformation ◽  
High Rate ◽  
Russian Economy ◽  
Stage Of Development ◽  
Qualitative Level ◽  
Rate Of Recovery

The transition of the Russian economy from plan to market is considered at a qualitative level. The analysis of economic dynamics in the transformation paradigm is conducted. The main stages of the transition process are discussed. Bonuses and costs due to the transition to market economy are considered. The reasons for the outstripping growth of well-being as compared to the growth of output are discussed. The signs of exhaustion of the potential of factors ensuring an abnormally high rate of recovery and accompanying welfare growth are discussed. The conclusion is made that the transformational recovery has been completed. The Russian economy has moved to the stage of development with relatively low growth rates of output and welfare, typical for stable (nontransition) economies.

Rapid in vivo induction of leukocyte tissue factor mRNA and protein synthesis following low dose endotoxin administration to rabbits

2001 ◽  
Vol 2 (3) ◽  
pp. 188-195 ◽  
Author(s):  
Tara C Brutzki ◽  
Myron J Kulczycky ◽  
Leslie Bardossy ◽  
Bryan J Clarke ◽  
Morris A Blajchman
Keyword(s):  
Protein Synthesis ◽  
Tissue Factor ◽  
Low Dose ◽  
Endotoxin Administration ◽  
In Vivo Induction

GLUT2 and hexokinase control proximodistal gradient of intestinal glucose metabolism in the newborn pig

1997 ◽  
Vol 272 (6) ◽  
pp. G1530-G1539 ◽  
Author(s):  
C. Cherbuy ◽  
B. Darcy-Vrillon ◽  
L. Posho ◽  
P. Vaugelade ◽  
M. T. Morel ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Glucose Transporter ◽  
Glucose Utilization ◽  
Specific Effect ◽  
Glucose Consumption ◽  
Utilization Rate ◽  
Glucose Turnover ◽  
Proximal Jejunum ◽  
A Site

We have reported previously that a high glycolytic capacity develops soon after birth in enterocytes isolated from suckling newborn pigs. In the present work, we investigated whether such metabolic changes could affect intestinal glucose utilization in vivo and examined possible variations in glucose metabolism along the small intestine. Glucose utilization by individual tissues was assessed using the 2-deoxyglucose technique. The overall glucose utilization rate was doubled in suckling vs. fasting 2-day-old pigs because of significantly higher rates in all tissues studied, except for the brain. In parallel, enterocytes were isolated from the proximal, medium, or distal jejunoileum of newborn vs. 2-day-old pigs and assessed for their capacity to utilize, transport, and phosphorylate glucose. Intestinal glucose consumption accounted for approximately 15% of glucose turnover rate in suckling vs. 8% in fasting pigs. Moreover, there was a proximal-to-distal gradient of glucose utilization in the intestinal mucosa of suckling pigs. Such a gradient was also evidenced on isolated enterocytes. The stimulation of both hexokinase activity (HK2 isoform) and basolateral glucose transporter (GLUT2), as observed in the proximal jejunum, could account for such a site-specific effect of suckling.

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