Patterns of DNase sensitivity in the chromosomes of Rana perezi (Amphibia: Anura)

Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 339-343 ◽  
Author(s):  
Pilar Herrero ◽  
Joaquina de la Torre ◽  
Jaime Gosálvez ◽  
Begoña Arano ◽  
Adrian T. Sumner
Keyword(s):  
Dnase I ◽  
Nick Translation ◽  
Chromosome Domains ◽  
Active Genes ◽  
Rana Perezi

We have analyzed the patterns of DNase I/nick translation in the chromosomes of Rana perezi. The results show a nonuniform DNase sensitivity in different chromosome domains; the hypersensitivity appears to be concentrated at both the NOR and the distal regions. The resemblance to the situation in mammals, where active genes are DNase I hypersensitive, is discussed.Key words: DNase sensitivity, chromosomes, Rana perezi.

The distribution of genes on human chromosomes as studied by in situ nick translation

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 890-894 ◽  
Author(s):  
J. de la Torre ◽  
A. T. Sumner ◽  
J. Gosalvez ◽  
L. Stuppia
Keyword(s):  
Cpg Islands ◽  
Dnase I ◽  
Human Chromosomes ◽  
Nick Translation ◽  
X Chromosomes ◽  
Dnase I Hypersensitivity ◽  
In Situ Nick Translation ◽  
Inactive X Chromosome ◽  
Active Genes

We have studied the distribution of potentially active genes on human chromosomes, using two methods: DNAse I hypersensitivity and restriction enzyme – nick translation with enzymes sensitive to methylation of CpG doublets. DNAse hypersensitivity is known to be associated with potentially active genes, and, when the reaction is detected by "in situ" nick translation, produces an R-banding pattern. Digestion of chromosomes with HpaII or CfoI, both of which should preferentially cut unmethylated sequences in the CpG islands associated with the majority of genes, also produces R-banding patterns. Deviations are attributable to overdigestion of the chromosomes, leading to extraction of DNA and loss of the specific sites that were to be detected. Contrary to the results of a number of previous workers, we have failed to demonstrate any differences between the DNAse I hypersensitivity or the degree of methylation of the active and inactive X chromosomes in metaphases from females.Key words: human chromosomes, gene distribution, DNAse I hypersensitivity, in situ nick translation, R-banding, CpG islands, DNA methylation, inactive X chromosome.

Patterns of DNase I sensitivity in the holocentric chromosomes of the aphid Megoura viciae

Genome ◽  
1998 ◽  
Vol 41 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Gian Carlo Manicardi ◽  
Mauro Mandrioli ◽  
Davide Bizzaro ◽  
Umberto Bianchi
Keyword(s):  
Dnase I ◽  
Holocentric Chromosomes ◽  
Telomeric Region ◽  
Nick Translation ◽  
In Situ Nick Translation ◽  
Embryo Cells ◽  
Dnase I Sensitivity ◽  
Megoura Viciae ◽  
Active Genes

Using the in situ nick translation technique, we looked for the presence of DNase I sensitive sites in Megoura viciae chromosomes, to study the distribution of active or potentially active genes in aphids, a group of insects possessing holocentric chromosomes. Cytological preparations obtained by the spreading of embryo cells were treated in situ with increasing concentrations (ranging from 5 to 200 ng/mL) of DNase I. At DNase I concentrations below 50 ng/mL, only one hypersensitive site was observed, and this was located on a telomeric region of the X chromosome that contains transcriptionally active nucleolar organizing regions, as assayed by silver staining. Interestingly, at intermediate concentrations of DNase, the incorporation of biotinylated nucleotide occurred uniformly throughout all chromosomes, whereas at concentrations above 100 ng/mL, a C-like banding pattern was produced. Our data differ from results obtained with mammalian, frog, and grasshopper chromosomes, where it was found that DNase I nicking is concentrated at the distal regions of all chromosomes.Key words: aphids, holocentric chromosomes, DNase I sensitivity, nick translation.

Nick translation of active genes in intact nuclei

1979 ◽  
Vol 69 (2) ◽  
pp. 496-505 ◽  
Author(s):  
Alexandra Levitt ◽  
Richard Axel ◽  
Howard Cedar
Keyword(s):  
Nick Translation ◽  
Active Genes

scholarly journals Gamma rays and bleomycin nick DNA and reverse the DNase I sensitivity of beta-globin gene chromatin in vivo.

1987 ◽  
Vol 7 (5) ◽  
pp. 1917-1924 ◽  
Author(s):  
B Villeponteau ◽  
H G Martinson
Keyword(s):  
Globin Gene ◽  
Dnase I ◽  
Globin Genes ◽  
Torsional Stress ◽  
Beta Globin ◽  
Cell Penetration ◽  
Dnase I Sensitivity ◽  
Chicken Erythrocytes ◽  
Active Genes

The active beta-globin genes in chicken erythrocytes, like all active genes, reside in large chromatin domains which are preferentially sensitive to digestion by DNase I. We have recently proposed that the special structure of chromatin in active domains is maintained by torsional stress in the DNA (Villeponteau et al., Cell 39:469-478, 1984). This hypothesis predicts that nicking of the DNA within any such chromosomal domain in vivo will relax the DNA and lead to loss of the special DNase I-sensitive state. Here we have tested this prediction by using gamma irradiation and bleomycin treatment to cleave DNA within intact chicken embryo erythrocytes. Both treatments cause reversal of DNase I sensitivity. Moreover, reversal occurs at approximately one nick per 150 kilobase pairs for both agents despite their entirely unrelated modes of cell penetration and DNA attack. These results suggest that the domain of DNase I sensitivity surrounding the beta-globin genes comprises 150 kilobase pairs of chromatin under torsional stress and that a single DNA nick in this region is sufficient to reverse the DNase I sensitivity throughout the entire domain.

scholarly journals DNase I nick translation in situ on meiotic chromosomes of the mouse, Mus musculus

1988 ◽  
Vol 90 (4) ◽  
pp. 629-634
Author(s):  
R. Raman ◽  
A.P. Singh ◽  
I. Nanda
Keyword(s):  
Sex Chromosomes ◽  
Mus Musculus ◽  
Meiotic Prophase ◽  
Cell Types ◽  
Dnase I ◽  
Translation Method ◽  
Nick Translation ◽  
Meiotic Chromosomes

DNase-I-sensitive sites have been located on the meiotic chromosomes of the mouse, Mus musculus, by the in situ DNase I nick-translation method. We find that: (1) of all the cell types studied, pachytene nuclei are the most sensitive to DNase I; (2) in diplotene the nicks occur preferentially in the vicinity of chiasmata; (3) the sex chromosomes are also sensitive to the enzyme despite their transcriptional quiescence; and (4) in the sex bivalent the nicks are primarily observed in the putative region of recombination. We conclude that, in addition to discriminating between the transcriptionally active and inactive states of chromatin, DNase I identifies recombination-specific chromatin changes in meiotic prophase.

A study of the localization of high mobility group proteins in chromatin

1978 ◽  
Vol 56 (6) ◽  
pp. 480-491 ◽  
Author(s):  
Beatriz Levy W. ◽  
Gordon H. Dixon
Keyword(s):  
Mouse Brain ◽  
High Mobility ◽  
Cell Types ◽  
Dnase I ◽  
High Mobility Group ◽  
Micrococcal Nuclease ◽  
Hmg Proteins ◽  
Calf Thymus ◽  
Limited Digestion ◽  
Active Genes

High mobility group (HMG) proteins from fetal calf thymus and mouse brain chromatin were purified and compared electrophoretically. The four major HMG proteins characteristic of fetal calf thymus chromatin (HMG's 1, 2, 14, and 17) were also found to be present in mouse brain chromatin.Nuclei from these two eucaryotic tissues were digested with DNase I and micrococcal nuclease and the acid-soluble proteins solubilized by the two nucleases in both tissues were analyzed on starch gels.Limited digestion of fetal calf thymus nuclei with DNase I led to the solubilization of a substantial fraction of proteins HMG-1 and HMG-2 together with smaller amounts of H1. In addition, limited digestion with micrococcal nuclease released approximately 70% of HMG's 1 and 2 and variable amounts of H1 into the soluble fraction. The observation that HMG proteins 1 and 2 are selectively solubilized under conditions in which active genes have been shown to be preferentially digested in various other cell types suggests their selective association with chromatin regions which are transcriptionally competent.

Evidence for the transcription of physiologically inactive rat-liver nucleolar chromatin by Escherichia coli RNA polymerase

1982 ◽  
Vol 2 (3) ◽  
pp. 155-161 ◽  
Author(s):  
Fu-Li Yu ◽  
Annabella Barrett
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Rat Liver ◽  
Dnase I ◽  
Rna Polymerase I ◽  
E Coli ◽  
Chromatin Template ◽  
Nucleolar Chromatin ◽  
Polymerase I ◽  
Active Genes

Rat-liver nucleoli (10–15 pg DNA) were digested with either 0.6 or 3 units of DNase I for various times (up to 1 h). RNA synthesis was then measured in the absence or presence ol 3 units of Escherichia coli RNA polymerase. It was found that the nucleolar chromatin supporting the endogenous engaged RNA polymerase I transcription was compl-etely destroyed in 3 min with either concentration of DNase I. The nucleolar chromatin template transcribed by E. coli RNA polymerase retained 50% of its original capacity even 60 min alter 3 units of DNase I digestion. When hybridization experiments were conducted, it was found that the DNAs derived from both levels of DNase-Idigested nucleoli were incapable of forming hybrids with the labelled nucleolar RNA synthesized by the engaged RNA polymerase I from the untreated nucleoli. Since the engaged RNA polymerase I transcribes only the physiologically active genes of the nucleolar chromatin, and the RNA transcripts represent active gene product, these data suggest that DNase I digestion has completely destroyed the active genes of the nucleolar chromatin, and E. coli RNA polymerase is able to transcribe the inactive nucleolar chromatin template.

scholarly journals In situ nick translation at the electron microscopic level: a tool for studying the location of DNAse I-sensitive regions within the cell.

1991 ◽  
Vol 39 (6) ◽  
pp. 871-874 ◽  
Author(s):  
M Thiry
Keyword(s):  
Ultrastructural Level ◽  
Dnase I ◽  
Electron Microscopic Level ◽  
Nick Translation ◽  
Dna Polymerase I ◽  
Electron Microscopic ◽  
Thin Sections ◽  
In Situ Nick Translation ◽  
Polymerase I

The in situ nick translation method was adapted to the ultrastructural level, to study the location of DNAse I-sensitive sequences within the cell. Ultra-thin sections of Lowicryl-embedded cells were incubated in a medium containing DNAse I, DNA polymerase I, and all four deoxyribonucleotides, some being biotinylated. The nick-translated sites were then visualized by an indirect immunogold labeling technique. The resulting labeling pattern is closely dependent on the DNAse I concentration in the nick-translation medium. The method reveals with great precision the specific DNAse I-sensitive regions within the nucleus. This technique can be used to discriminate between active and inactive regions of interphase chromatin.

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