Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Compact structure of ribosomal chromatin in Xenopus laevis.
Spadafora C, Crippa M.
???displayArticle.abstract???
Micrococcal nuclease digestion was used as a tool to study the organization of the ribosomal chromatin in liver, blood and embryo cells of X. laevis. It was found that in liver and blood cells, ribosomal DNA is efficiently protected from nuclease attack in comparison to bulk chromatin. Although ribosomal chromatin is fragmented in a typical nucleosomal pattern, a considerable portion of ribosomal DNA retains a high molecular weight even after extensive digestion. A greater accessibility of the coding region in comparison to the non-coding spacer was found. In embryos, when ribosomal DNA is fully transcribed, these genes are even more highly protected than in adult tissues: in fact, the nucleosomal ladder can hardly be detected and rDNA is preserved in high molecular weight. Treatment of chromatin with 0.8 M NaCl abolishes the specific resistance of the ribosomal chromatin to digestion. The ribosomal chromatin, particularly in its active state, seems to be therefore tightly complexed with chromosomal proteins which protect its DNA from nuclease degradation.
Bellard,
Disruption of the typical chromatin structure in a 2500 base-pair region at the 5' end of the actively transcribed ovalbumin gene.
1982, Pubmed
Bellard,
Disruption of the typical chromatin structure in a 2500 base-pair region at the 5' end of the actively transcribed ovalbumin gene.
1982,
Pubmed Boseley,
Sequence organization of the spacer DNA in a ribosomal gene unit of Xenopus laevis.
1979,
Pubmed
,
Xenbase Burgoyne,
Mammalian chromatin substructure studies with the calcium-magnesium endonuclease and two-dimensional polyacrylamide-gel electrophoresis.
1974,
Pubmed Camerini-Otero,
Nucleosomal packaging of the thymidine kinase gene of herpes simplex virus transferred into mouse cells: an actively expressed single-copy gene.
1980,
Pubmed Giri,
DNase I sensitivity of ribosomal genes in isolated nucleosome core particles.
1980,
Pubmed Igo-Kemenes,
Chromatin.
1982,
Pubmed Labhart,
Structure of the active nucleolar chromatin of Xenopus laevis Oocytes.
1982,
Pubmed
,
Xenbase Levy,
Chromatin fine structure of active and repressed genes.
1981,
Pubmed Lohr,
Detailed analysis of the nucleosomal organization of transcribed DNA in yeast chromatin.
1981,
Pubmed Mathis,
Subunit structure of rDNA-containing chromatin.
1976,
Pubmed Ness,
Chromatin structure along the ribosomal DNA of Dictyostelium. Regional differences and changes accompanying cell differentiation.
1983,
Pubmed Piper,
Tetrahymena ribosomal RNA gene chromatin is digested by micrococcal nuclease at sites which have the same regular spacing on the DNA as corresponding sites in the bulk nuclear chromatin.
1976,
Pubmed Pruitt,
A mosaicism in the higher order structure of Xenopus oocyte nucleolar chromatin prior to and during ribosomal gene transcription.
1981,
Pubmed
,
Xenbase Reeves,
Ribosomal genes of Xenopus laevis: evidence of nucleosomes in transcriptionally active chromatin.
1976,
Pubmed
,
Xenbase Rigby,
Labeling deoxyribonucleic acid to high specific activity in vitro by nick translation with DNA polymerase I.
1977,
Pubmed Scheer,
Structural organization of spacer chromatin between transcribed ribosomal RNA genes in amphibian oocytes.
1980,
Pubmed
,
Xenbase Southern,
Detection of specific sequences among DNA fragments separated by gel electrophoresis.
1975,
Pubmed Spadafora,
Rearrangement of chromatin structure induced by increasing ionic strength and temperature.
1979,
Pubmed Spinelli,
Chromatin structure of histone genes in sea urchin sperms and embryos.
1982,
Pubmed Weischet,
Protection of expressed immunoglobulin genes against nuclease cleavage.
1983,
Pubmed Wu,
The chromatin structure of specific genes: II. Disruption of chromatin structure during gene activity.
1979,
Pubmed
