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Showing 1 to 20 of 50 for “"vitellogenin"”.
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Estrogen Receptor Regulation of Vitellogenin Gene Expression
… biosynthesis of the egg yolk protein precursor vitellogenin in the liver. Injection of estrogen into male animals previously exposed to estrogen but subsequently withdrawn from the hormone leads to the much earlier appearance of vitellogenin mRNA and a four-fold higher rate of vitellogenin gene …
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Chromatin Structure, Dna Methylation and Vitellogenin Gene Expression
… and the chromatin conformation of the Xenopus vitellogenin genes were examined to determine their relationship to the transcriptional state of the genes. The role of these two potential regulatory mechanisms was of particular interest because the estrogen induction of vitellogenin mRNA does not …
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Estrogen Receptor Regulation of Xenopus Laevis Vitellogenin Gene Expression
… mediates the transcriptional response of the vitellogenin gene was investigated. The Xenopus estrogen receptor (XER) cDNA was cloned and sequenced. It could encode a protein of 66 Kd, which is approximately the same size as human and chicken estrogen receptors. Most of the amino acid homology …
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Estrogen Regulates Vitellogenin Gene Transcription and Messenger-Rna Degradation in Xenopus Laevis Liver
Vitellogenin gene transcription and mRNA degradation rates were measured in Xenopus laevis liver using pulse labeling and pulse chase techniques. Estrogen regulates the accumulation of vitellogenin mRNA through three processes: (1) There is a selective transcriptional activation of the vitellogenin …
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DNA sequences required for efficient transcription of the estrogen regulated Xenopus laevis vitellogenin promoter
… liver cells of Xenopus laevis expression of the vitellogenin genes is tightly regulated by estrogen. Estrogen activates gene transcription by binding as estradiol-estrogen receptor complex to estrogen response elements (EREs) in the 5$\sp\prime$-flanking region of target genes. In order to …
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Temporal Expression and Transcriptional Regulation of the Vitellogenin Receptor Gene In Largemouth Bass (Micropterus Salmoides)
<p>Fish vitellogenin (VTG) synthesized and released from the liver of oviparous animals is taken up into oocytes, in part, by the vitellogenin receptor (VtgR). Some studies have focused on the functional role of VtgR in fish; however the transcriptional control of this gene has not been …
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Polysomes but not translation are required for estradiol-mediated stabilization of Xenopus laevis vitellogenin mRNA
… mediated stabilization of Xenopus laevis vitellogenin mRNA was examined. Using a method developed for total liver polysome preparation, the efficiency of translation of vitellogenin mRNA was determined by examining the distribution of the vitellogenin polysomes within total polysomes …
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The effect of dietary zinc level upon the efficiency of vitellogenin synthesis by male quail
… Japanese quail were sacrificed and vitellogenin (phosphoprotein) production was assessed in these birds by analyzing plasma for protein-bound phosphorus concentrations (PBP). Plasma PBP concentrations of estrogen-injected male quails increased from undetectable values for control …
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Vitellogenin induction in male Japanese medaka exposed to the chemotherapeutics: oxytetracycline, Romet-30, and copper sulfate
The specificity of a medaka vitellogenin (Vtg) enzyme-linked immunosorbent assay (ELISA) kit was tested on adult hybrid tilapia to determine if vitellogenin could be successfully measured in tilapia using this method. Adult hybrid (Orechromis niloticus x Oreochromis mossambicus x Oreochromis …
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Vitellogenesis in <i>Hyalomma dromedarii</i> (Acari: Ixodidae): A Model for Analysis of Endocrine Regulation in Ixodid Ticks
… vitellins, and their hemolymph precursors, vitellogenins, were characterized in the ixodid tick <em>Hyalomma dromedarii.</em> Three vitellins were identified. The high molecular weight vitellins, VN A and VN B, were composed of seven homologous molecular weight subunit polypeptides, VN 1-7. …
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Patterns of intersex prevalence, vitellogenin, and reproductive condition in two commercially harvested fish along a pollution gradient in the Illinois River complex
… elevated levels of the blood lipoprotein vitellogenin (VTG), and decreased reproduction. However, assessments of the prevalence and distribution of VTG and intersex in wild fish populations are necessary and few have been performed on the Illinois River. Such field studies may provide …
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Neuroendocrine Mechanisms Involved in the Control of Ovarian Development and Vitellogenesis in the Rainbow Trout
… of oestrone, oestradiol-17B, testosterone, vitellogenin and calcium and these correlated with histological data both during the reproductive cycle and after treatment with hormones. Single and double injections of oestradiol-17B respectively produced primary and much more rapid secondary …
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The Effect of Estrogen on Regulatory Enzyme Levels and Albumin Gene Expression in Xenopus Laevis Hepatocytes
The estrogen induced synthesis of vitellogenin in male Xenopus laevis is a unique system in which to study the molecular mechanism of hormone action on gene expression. Following administration of estradiol-17 to male Xenopus laevis a specific set of egg yolk proteins together with all components …
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Influence of Insulin, Insulin-Like Growth Factor I and Sex Steroids On the Regulation of the Vitellogenin Receptor In Developing Oocytes of Largemouth Bass (Micropterus Salmoides)
<p> Fish vitellogenin synthesized and released from the liver of oviparous animals is taken up into oocytes by the vitellogenin receptor (<italic>vtgr</italic>). This is an essential process in providing nutrient yolk to developing embryos to ensure successful reproduction. Here we disclose the LMB …
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Assessment of the Efficacy of a Constructed Wetland to Reduce or Remove Wastewater Effluent Estrogenicity and Toxicity Using Biomarkers in Male Fathead Minnows (Pimephales Promelas Rafinesque, 1820)
Vitellogenin in Pimephales promelas was used to assess estrogenicity of a local municipal effluent. Vitellogenin induction in male P. promelas increased in frequency and magnitude with increased exposure duration and was greater ("=0.05) than controls after 2 and 3 weeks of exposure. The level of …
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Modeling the effects of endocrine disrupting chemicals on Atlantic croaker: understanding biomarkers and predicting population responses
… secretion of gonadotropin to the production of vitellogenin. I simulated the effects of three environmental stressors that affect vitellogenin production differently. Model simulations demonstrated that it is possible to relate contaminant-induced changes in biomarkers to vitellogenin production …
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Functional Analysis of the 15 KH Domain Human Nucleic Acid Binding Protein, Vigilin
… which binds to the 3' untranslated region of vitellogenin mRNA following estrogen induction. By binding to this region of vitellogenin mRNA, vigilin protects the mRNA from cleavage by the endonuclease PMR-1 and causes the message to be stabilized. Given its identification in various systems by …
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Blood characteristics as predictors of reproductive success in quail species exposed to DDT
… Experiments were performed to evaluate vitellogenin, vitamin A, and vitamin E as biomarkers of contamination with DDT, an organochlorine pesticide, and reproductive success in Japanese quail (Coturnix coturnix japonica) or northern bobwhites (Colinus virginianus). The utility of …
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Molecular analyses of endocrine and nutritional factors that affect division of labor and health in honey bees (Apis mellifera)
… by which a peripheral storage protein, vitellogenin, regulates foraging onset. Using RNA interference and gene expression profiling, I show that vitellogenin elicits a strong transcriptomic response in the brain that closely resembles the response elicited by another key regulator of …
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Storage and Utilization of Hexamerin Proteins in the Pitcher Plant Mosquito, Wyomyia Smithii
… of hexamerin proteins for egg protein, vitellogenin, synthesis. W. smithii from North Carolina utilize majority of stored hexamerins in 30 hours after emergence with simultaneous increase in vitellogenins. Those from Georgia retain hexamerins for up to 42 hours and vitelliogenins build …
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