scholarly journals Variations in heterochromatin content reveal important polymorphisms for studies of genetic improvement in garlic (Allium sativum L.)

2023 ◽  
Vol 83 ◽  
Author(s):  
P. A. A. Bacelar ◽  
L. L. Feitoza ◽  
S. E. S. Valente ◽  
R. L. F. Gomes ◽  
L. V. Martins ◽  
...  
Keyword(s):  
Allium Sativum ◽  
Chromatin Condensation ◽  
Chromosome 6 ◽  
Germplasm Bank ◽  
Chromomycin A3 ◽  
Interphase Nuclei ◽  
Karyotype Formula ◽  
Heterochromatin Content ◽  
Nutraceutical Properties ◽  
Internal Consumption

Abstract Allium sativum L. is an herb of the Alliaceae family with a specific taste and aroma and medicinal and nutraceutical properties that are widely marketed in several countries. Brazil is one of the largest importers of garlic in the world, despite of its production is restricted and limited to internal consumption. Thus, explore the genetic diversity of commercial garlic conserved at germplasm banks is essential to generate additional genetic information about its economically important crop. A suitable tool for this purpose is the cytogenetic characterisation of these accessions. This study aimed to characterise the cytogenetic diversity among seven accessions of garlic from a Germplasm Bank in Brazil. The karyotypes were obtained by conventional staining and with chromomycin A3 (CMA) and 4,6-diamidino-2-phenylindole (DAPI) fluorochromes. All accessions analysed showed chromosome number 2n = 16, karyotype formula 6M+2SM, symmetrical karyotypes, reticulate interphase nuclei, and chromosomes with uniform chromatin condensation from prophase to metaphase. The fluorochromes staining showed differences in the amount and distribution of heterochromatin along the chromosomes and between accessions studied. Based on the distribution pattern of these small polymorphisms, it was possible to separate the seven accessions into three groups. It was also possible to differentiate some of the accessions individually. One of the results obtained showed a heteromorphic distension of the nucleolar organiser region observed on the chromosome pairs 6 or 7 with peculiar characteristics. It was suggested for example, that the heteromorphic block of heterochromatin (CMA+++/DAPI-) on chromosome 6 of the “Branco Mineiro Piauí” accession can be used as a marker to identify this genotype or may be associated with some character of economic interest.

scholarly journals Mitotic chromatin condensation in vitro using somatic cell extracts and nuclei with variable levels of endogenous topoisomerase II.

1990 ◽  
Vol 111 (6) ◽  
pp. 2839-2850 ◽  
Author(s):  
E R Wood ◽  
W C Earnshaw
Keyword(s):  
Topoisomerase Ii ◽  
Condensation Reaction ◽  
Chromatin Condensation ◽  
Condensation Process ◽  
Interphase Nuclei ◽  
Culture Cells ◽  
Cell Extracts ◽  
Topo Ii ◽  
Species Specific

We report the development of a new method for producing mitotic extracts from tissue culture cells. These extracts reproducibly promote the condensation of chromatin in vitro when incubated with purified interphase nuclei. This condensation reaction is not species specific, since nuclei from chicken, human, and hamster cell lines all undergo chromatin condensation upon incubation with the extract. We have used this extract to investigate the role of DNA topoisomerase II (topo II) in the chromosome condensation process. Chromatin condensation does not require the presence of soluble topo II in the mitotic extract. However, the extent of formation of discrete chromosome-like structures correlates with the level of endogenous topo II present in the interphase nuclei. Our results further suggest that chromatin condensation in this extract may involve two processes: chromatin compaction and resolution into discrete chromosomes.

Chromatin Condensation: Chromomycin A3 (CMA3) Stain

2021 ◽  
pp. 151-155
Author(s):  
Sara Marchiani ◽  
Lara Tamburrino ◽  
Francesca Benini ◽  
Sandra Pellegrini ◽  
Elisabetta Baldi
Keyword(s):  
Chromatin Condensation ◽  
Chromomycin A3

scholarly journals Label-Free Evaluation of Chromatin Condensation in Human Normal Morphology Sperm Using Raman Spectroscopy

2021 ◽  
Author(s):  
M. Y. Jahmani ◽  
M. E. Hammadeh ◽  
M. A. Al Smadi ◽  
Marko K. Baller
Keyword(s):  
Raman Spectroscopy ◽  
Dna Fragmentation ◽  
Raman Spectra ◽  
Chromatin Condensation ◽  
Function Evaluation ◽  
Label Free ◽  
Chromomycin A3 ◽  
Normal Morphology ◽  
Acridine Orange Staining ◽  
Significant Difference

AbstractChromatin condensation is one of the main factors essential for sperm function. Evaluation of chromatin condensation by current methods render the assessed sperm unsuitable for assisted reproduction. We examined the Raman spectra of normal morphology sperm to determine whether a non-invasive confocal Raman spectroscopy can detect spectral differences between groups having different levels of chromatin condensation. Semen samples from 85 donors who underwent ICSI were obtained. Chromomycin A3, aniline blue and acridine orange staining were performed to evaluate the protamine deficiency, histone retention and DNA fragmentation respectively. Raman spectra were obtained from 50 normal morphology sperm for each donor. Spectral analysis was performed using home written programs in LabVIEW software and samples were grouped based on chromomycin A3 staining. Raman peaks intensities at 670 cm-1, 731 cm-1, 785 cm-1, 858 cm-1, 1062 cm-1, 1098 cm-1, 1185 cm-1, 1372 cm-1, 1424 cm-1, 1450 cm-1, 1532 cm-1, 1618 cm-1 and 1673 cm-1 were significantly correlated with at least one of the sperm staining methods. The median intensity of the Raman peaks at 670 cm-1, 731 cm-1, 785 cm-1, 1062 cm-1, 1098 cm-1, 1185 cm-1, 1372 cm-1, 1424 cm-1, 1450 cm-1, 1532 cm-1, 1618 cm-1 and 1673 cm-1 show a significant difference between the CMA3≤41 and CMA3>41groups. The Raman spectroscopic measurements represent a promising diagnostic tool that has the ability to label-free detect sperm with chromatin abnormalities, such as improper chromatin condensation and DNA fragmentation to a certain degree similar to that of the existing staining techniques at the individual cell level.

PML bodies associate specifically with the MHC gene cluster in interphase nuclei

2001 ◽  
Vol 114 (20) ◽  
pp. 3705-3716 ◽  
Author(s):  
Carol Shiels ◽  
Suhail A. Islam ◽  
Radost Vatcheva ◽  
Peter Sasieni ◽  
Michael J. E. Sternberg ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Chromosomal Location ◽  
Human Fibroblasts ◽  
Genomic Region ◽  
Promyelocytic Leukemia ◽  
Chromosome 6 ◽  
Interphase Nuclei ◽  
Spatial Organisation ◽  
Nuclear Compartment ◽  
Pml Bodies

Promyelocytic leukemia (PML) bodies are nuclear multi-protein domains. The observations that viruses transcribe their genomes adjacent to PML bodies and that nascent RNA accumulates at their periphery suggest that PML bodies function in transcription. We have used immuno-FISH in primary human fibroblasts to determine the 3D spatial organisation of gene-rich and gene-poor chromosomal regions relative to PML bodies. We find a highly non-random association of the gene-rich major histocompatibilty complex (MHC) on chromosome 6 with PML bodies. This association is specific for the centromeric end of the MHC and extends over a genomic region of at least 1.6 megabases. We also show that PML association is maintained when a subsection of this region is integrated into another chromosomal location. This is the first demonstration that PML bodies have specific chromosomal associations and supports a model for PML bodies as part of a functional nuclear compartment.

scholarly journals Chromosome number and secondary constriction variation in 51 accessions of a citrus germplasm bank

1997 ◽  
Vol 20 (3) ◽  
pp. 489-496 ◽  
Author(s):  
Marcelo Guerra ◽  
Andrea Pedrosa ◽  
Ana Emília Barros e Silva ◽  
Maria Tereza Marquim Cornélio ◽  
Karla Santos ◽  
...  
Keyword(s):  
Secondary Constriction ◽  
Chromatin Condensation ◽  
Proximal Region ◽  
Citrus Species ◽  
Germplasm Bank ◽  
Mitotic Chromosomes ◽  
Citrus Germplasm ◽  
Numerical Variation ◽  
Subterminal Region ◽  
Secondary Constrictions

The mitotic chromosomes of 51 citrus accessions from the Centro Nacional de Pesquisa em Mandioca e Fruticultura Tropical, Cruz das Almas, BA, Brazil, were analyzed. The sample included representatives of 20 Citrus species, one of Poncirus and seven hybrids. All accessions showed 2n = 18 without any evidence of numerical variation. The most clearly variable karyotype feature was the number and position of secondary constrictions (SECs). In 19 accessions the SECs were not identified, mainly due to the degree of chromatin condensation. In the remainder they varied in number from one to three per karyotype. They were found in the proximal region of one of the three largest chromosome pairs, in the terminal/subterminal region of a smaller chromosome or, more seldom, terminally in a larger chromosome. Only in a few cases were such constrictions observed simultaneously in both homologues of the same chromosome pair. The high variability of this karyotype feature may be due to the activation of this region in the previous interphase but may also indicate a high structural variability and heterozygosity of citrus germplasms

Detection and mapping of interactions between chromatin and the nuclear envelope in drosophila embryos

1995 ◽  
Vol 53 ◽  
pp. 764-765
Author(s):  
W.F. Marshall ◽  
A.F. Dernburg ◽  
B. Harmon ◽  
J.W. Sedat
Keyword(s):  
Nuclear Envelope ◽  
Chromatin Condensation ◽  
Three Dimensional ◽  
Physiological Role ◽  
Nuclear Surface ◽  
Intact Cells ◽  
Molecular Determinants ◽  
Surface Harmonic ◽  
Drosophila Embryos

Interactions between chromatin and nuclear envelope (NE) have been implicated in chromatin condensation, gene regulation, nuclear reassembly, and organization of chromosomes within the nucleus. To further investigate the physiological role played by such interactions, it will be necessary to determine which loci specifically interact with the nuclear envelope. This will not only facilitate identification of the molecular determinants of this interaction, but will also allow manipulation of the pattern of chromatin-NE interactions to probe possible functions. We have developed a microscopic approach to detect and map chromatin-NE interactions inside intact cells.Fluorescence in situ hybridization (FISH) is used to localize specific chromosomal regions within the nucleus of Drosophila embryos and anti-lamin immunofluorescence is used to detect the nuclear envelope. Widefield deconvolution microscopy is then used to obtain a three-dimensional image of the sample (Fig. 1). The nuclear surface is represented by a surface-harmonic expansion (Fig 2). A statistical test for association of the FISH spot with the surface is then performed.

Effects of Mg2+ on Chromatic Structure in Isolated Chicken Liver Nuclei

1990 ◽  
Vol 48 (3) ◽  
pp. 130-131
Author(s):  
Soichiro Arai ◽  
Yuh H. Nakanishi
Keyword(s):  
Chromatin Structure ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Divalent Cations ◽  
Chromatin Condensation ◽  
Chicken Liver ◽  
Electron Microscopic ◽  
Razor Blade ◽  
Microscopic Studies ◽  
Liver Nuclei

Although many electron microscopic studies on extracted chromatin have provided considerable information on chromatin condensation induced by divalent cations, there is only a little literature available on the effects of divalent cations on chromatin structure in intact nuclei. In the present study, the effects of Mg2+ on chromatin structure in isolated chicken liver nuclei were examined over a wide concentration range of Mg2+ by scanning electron microscopy.Nuclei were prepared from chicken liver by the method of Chauveau et al. with some modifications. The nuclei were suspended in 25 mM triethanolamine chloride buffer (pH7.4) with 1 mM EDTA or in the buffer with concentrations of MgCl2 varying from 1 to 50 mM. After incubation for 1 min at 0°C, glutaraldehyde was added to 1.8% and the nuclei were fixed for 1 h at 4°C. The fixed nuclei were mixed with 15% gelatin solution warmed at about 40°C, and kept at room temperature until the mixture set. The gelatin containing the nuclei was fixed with 2% glutaraldehyde for 2-4 h, and cut into small blocks. The gelatin blocks were conductive-stained with 2% tannic acid and 2% osmium tetroxide, dehydrated in a graded series of ethanol, and freeze-cracked with a razor blade in liquid nitrogen.

Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

1996 ◽  
Vol 54 ◽  
pp. 758-759
Author(s):  
D. W. Fairbain ◽  
M.D. Standing ◽  
K.L. O'Neill
Keyword(s):  
Heat Shock ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Resistant Cell ◽  
Membrane Blebbing ◽  
Late Loss ◽  
Induced Apoptosis ◽  
Dying Cells ◽  
In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

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