Nuclei With Alpha Structure
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. "Study of the Elastic Scattering Between Nuclei Light Heavy Radioactive Stable" / "Estudo do Espalhamento Elástico Entre Núcleos Pesados Leves Estáveis e Radioativos"
The angular distributions of the elastic scattering for the 12C+28Si and 6He+27Al systems have been measured, in energies close to the Coulomb barrier. For the 12C+28Si system the data were obtained at energies Ec.m. = 12.4 - 25.2MeV and to 6He+27Al system were measured four energies Elab = 9.5, 11, 12 and 13.4MeV. The analysis of the angular distributions w
Publicado em: 2006
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2. Chromatin structure of histone genes in sea urchin sperms and embryos.
The nucleosomal organization of active and repressed alpha subtype histone genes has been investigated by micrococcal nuclease digestion of P. lividus sperm, 32-64 cell embryo and mesenchyme blastula nuclei, followed by hybridization with 32P-labeled specific DNA probes. In sperms, fully repressed histone genes are regularly folded in nucleosomes, and exhibi
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3. The effect of salt extraction on the structure of transcriptionally active genes; evidence for a DNAseI-sensitive structure which could be dependent on chromatin structure at levels higher than the 30 nm fibre.
The procedure developed by Lawson and Cole (Biochemistry, 1979, 18 2161-2166) for removing lysine-rich histones from nuclei at low pH also quantitatively extracts proteins HMG14 and 17. The effect of this low pH extraction on the DNAseI-sensitive structures of active genes in avian red blood cells has been investigated. No major perturbation of a development
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4. A transfer RNAArg gene of Pelargonium chloroplasts, but not a 5S RNA gene, is efficiently transcribed after injection into Xenopus oocyte nuclei.
We present the primary structure of a chloroplast tRNAArgACG gene of the plant, Pelargonium zonale, and its faithful expression in Xenopus oocyte nuclei. This tRNAArg gene is located 250 bp downstream of a 5S RNA gene within a cloned 5kb long ribosomal DNA segment (Fig. 1). The Pelargonium tRNAArg gene shares 97% and 86% sequence homology with tRNAArgACG gen
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5. Hepatocyte nuclear factor 1alpha gene inactivation impairs chromatin remodeling and demethylation of the phenylalanine hydroxylase gene.
Hepatocyte nuclear factor 1 alpha (HNF1alpha) is a homeoprotein that is expressed in the liver, kidney, pancreas, and digestive tract. Its inactivation in mouse resulted in decreased transcription of known target genes such as albumin and alpha1-antitrypsin. In contrast, the phenylalanine hydroxylase (PAH) gene was totally silent and unresponsive to normal i
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6. Subunit structure of alpha-satellite DNA containing chromatin from African green monkey cells.
alpha-Satellite DNA containing chromatin from African green monkey cells (CV-1 cells) has been used to study the question whether or not nucleosomes are arranged in phase with the 172 bp repeat unit of the satellite DNA. Digestion experiments with DNAase II led us to exclude a simple phase relationship between the nucleosomal and the satellite DNA repeats. D
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7. Discontinuous DNA replication of Drosophila melanogaster is primed by octaribonucleotide primer.
To investigate the precise structure of eucaryotic primer RNA made in vivo, short DNA chains isolated from nuclei of Drosophila melanogaster embryos were analyzed. Post-labeling of 5' ends of short DNA chains with polynucleotide kinase and [gamma-32P]ATP revealed that 7% of the DNA fragments were covalently linked with mono- to octaribonucleotide primers at
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8. Chromatin structure and DNase I hypersensitivity in the transcriptionally active and inactive porcine tumor necrosis factor gene locus.
We have analyzed the chromatin structure of the porcine tumor necrosis factor gene locus (TNF-alpha and TNF-beta). Nuclei from porcine peripheral blood mononuclear cells were digested with different nucleases. As assessed with micrococcal nuclease, the two TNF genes displayed slightly faster digestion kinetics than bulk DNA. Studies with DNaseI revealed dist
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9. Assembly of nuclear ribonucleoprotein particles during in vitro transcription.
The assembly of heterogeneous nuclear RNA (hnRNA) into ribonucleoprotein (RNP) particles has been investigated during in vitro transcription in isolated nuclei. Approximately 80% of the in vitro transcription observed in mouse Friend erythroleukemia cell nuclei is attributable to the activity of RNA polymerase II. In vitro hnRNA transcripts are assembled int
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10. Visualization of focal sites of transcription within human nuclei.
HeLa cells were encapsulated in agarose microbeads, permeabilized and incubated with Br-UTP in a 'physiological' buffer; then sites of RNA synthesis were immunolabelled using an antibody that reacts with Br-RNA. After extending nascent RNA chains by < 400 nucleotides in vitro, approximately 300-500 focal synthetic sites can be seen in each nucleus by fluores
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11. Primer RNA for DNA synthesis on single-stranded DNA template in a cell free system from Drosophila melanogaster embryos.
A cytoplasmic extract of Drosophila melanogaster early embryos supported DNA synthesis which was dependent on an added single stranded DNA template, phi X174 viral DNA. The product DNA made during early reaction was about 100 to 600 nucleotides in length and complementary to the added template. After alkali treatment, 70 to 80 per cent of the product DNA cha
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12. Structure of a poly (adenosine diphosphoribose) monomer: 2'-(5"-hosphoribosyl)-5'-adenosine monophosphate.
A preparation of poly(adenosine diphosphoribose) synthase obtained from pigeon liver nuclei has been used to make poly(adenosine diphosphoribose) with an average chain length of 20. Digestion of the purified poly(adenosine diphosphoribose) with snake venom phosphodiesterase (oligonucleate 5'-nucleotidohydrolase; EC 3.1.4.1) gave the monomer, 2'-(5"-phosphori