A Quantitative Analysis of Radiation-Induced Chromosome Aberrations with a Fluorescent Digital Image Microscope (original) (raw)
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Cytometry, 1990
Chromosomal in situ suppression (CISS)-hybridization of biotinylated phage DNA-library inserts from sorted human chromosomes was used to decorate chromosomes 1 and 7 specifically from pter to qter and to detect structural aberrations of these chromosomes in irradiated human peripheral lymphocytes. In addition, probe pUC1.77 was used to mark the 1q12 subregion in normal and aberrant chromosomes 1. Low LET radiation (60Co-gamma-rays; 1.17 and 1.33 MeV) of lymphocyte cultures was performed with various doses (D = 0, 2, 4, 8 Gy) 5 h after stimulation with phytohaemagglutinin. Irradiated cells were cultivated for an additional 67 h before Colcemid arrested metaphase spreads were obtained. Aberrations of the specifically stained chromosomes, such as deletions, dicentrics, and rings, were readily scored after in situ hybridization with either the 1q12 specific probe or DNA-library inserts. By the latter approach, translocations of the specifically stained chromosomes could also be reliably...
The persistence of aberrations in mice induced by gamma radiation as measured by chromosome painting
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1996
Fluorescence in situ hybridization, or chromosome painting, has become an invaluable tool in the cytogenetic evaluation of historical or chronic exposure because it can be used to detect stable genetic damage, such as translocations, which persist through cell division, quickly and easily. The recent development of chromosome-specific composite DNA probes for the mouse has allowed the use of chromosome painting in this commonly used animal model. In order to measure the persistence of radiation-induced translocations, C57BL/6 female mice were given a whole body acute dose of 0, 1, 2, 3 or 4 Gy '37Cs gamma rays at 8 weeks of age. Metaphase chromosomes from both peripheral blood and bone marrow cells were obtained from four mice in each dose group at 1, 8, 15 and 30 days post-irradiation. Chromosomes 2 and 8 were painted, while the remaining chromosomes were counterstained with propidium iodide. DAPI counterstain was used to differentiate between translocations and dicentrics because it brightly labels the centromeric heterochromatin. The equivalent of 100 cells from each tissue was scored from each mouse. The results show that the percentage of reciprocal translocations, at least at doses of 3 Gy or lower, did not decrease with time in either tissue. In contrast, the frequency of non-reciprocal translocations induced by doses of 3 Gy or lower, remained unchanged in the peripheral blood, but decreased after a week in the bone marrow, then remained constant. An increase in these two types of aberration was observed between 15 and 30 days in the bone marrow and may have been due to clonal expansion. Dicentrics decreased with time in both tissues, almost none remained in the bone marrow after 8 days. These data suggest that reciprocal translocations are persistent and will serve as an effective biodosimeter for radiation exposure.
Radiation Measurements, 2011
A modified C-band technique was developed in order to analyze more accurately dicentric, tricentric, and ring chromosomes in irradiated human peripheral lymphocytes. Instead of the original method relying on treatment with barium hydroxide Ba(OH) 2 , C-bands were obtained using a modified form of heat treatment in formamide followed with DAPI staining. This method was tentatively applied to the analysis of dicentric chromosomes in irradiated human lymphocytes to examine its availability. The frequency of dicentric chromosome was almost the same with conventional Giemsa staining and the modified C-band technique. In the analysis using Giemsa staining, it is relatively difficult to identify the centromere on the elongated chromosomes, over-condensed chromosomes, fragment, and acentric ring. However, the modified C-band method used in this study makes it easier to identify the centromere on such chromosomes than with the use of Giemsa staining alone. Thus, the modified C-band method may give more information about the location of the centromere. Therefore, this method may be available and more useful for biological dose estimation due to the analysis of the dicentric chromosome in human lymphocytes exposed to the radiation. Furthermore, this method is simpler and faster than the original C-band protocol and fluorescence in situ hybridization (FISH) method with the centromeric DNA probe.
Quantitative analysis of radiation-induced chromosome aberrations
Cytogenetic and Genome Research, 2004
We review chromosome aberration modeling and its applications, especially to biodosimetry and to characterizing chromosome geometry. Standard results on aberration formation pathways, randomness, dose-response, proximity effects, transmissibility, kinetics, and relations to other radiobiological endpoints are summarized. We also outline recent work on graph-theoretical descriptions of aberrations, Monte-Carlo computer simulations of aberration spectra, software for quantifying aberration complexity, and systematic links of apparently incomplete with complete or truly incomplete aberrations.
Chromosome content and ultrastructure of radiation-induced micronuclei
Mutagenesis, 1996
Unrepaired or misrepaired radiation damage in mammalian chromosomes can result in micronucleus formation at the first cell division. This represents loss of genomic information which may cause cell death. To improve our understanding of the mechanism of radiation-induced micronucleus formation, we characterized micronucleus ultrastructure and identified the origin of micronucleus DNA. Immunofluorescence microscopy showed that micronuclei were structurally similar to main nuclei since they contained nuclear lamins A and C and were encapsulated by a network of vimentin intermediate filaments. The contents of radiation-induced micronuclei were characterized using fluorescence in situ hybridization to probe for DNA originating from chromosomes 2, 7, 11 and 16. We postulated that if incorporation of DNA into micronuclei were random, then the probability of chromosomal DNA in micronuclei would be related to the target, i.e. chromosome size. Our results demonstrated that incorporation of DNA from smaller chromosomes (11 and 16) was not different from expected values but incorporation of DNA from the larger chromosomes (2 and 7) was significantly greater than expected. Not all chromosomes in the human genome, therefore, were equally susceptible to genomic loss by micronucleus encapsulation. In conclusion, radiationinduced micronuclei have similar structural characteristics to main nuclei, chromosome damage and/or repair after ionizing radiation may be non-random, and micronucleus formation may reflect this variability.
Biology Bulletin, 2019
Examples of the use of different types of chromosome aberrations as diagnostic indicators to solve the practical problems of radioecology were considered. The classifications of the chromosome aberrations used to estimate the clastogenic effect of factors of radiation and chemical nature according to the results of cytogenetic studies with uniform staining of the chromosomes were analyzed. Some terminological inconsistency and ambiguity when designating various types and categories of chromosome aberrations, reflecting the clastogenic effect, was detected. It was demonstrated that this inconsistency can complicate the use of such cytogenetic indices in radioecological practice. According to the results of the Allium test using a digital imaging system, original microimages demonstrating the configurations of aberrant chromosomes used in classifications were obtained.
Mutagenesis, 1997
A multicolour tandem labelling fluorescence in situ hybridization (FISH) procedure was used to compare the frequencies of radiation-induced chromosome breakage and hyperdiploidy of chromosome 1 occurring in non-cultured granulocytes and Go lymphocytes with those observed in cultured metaphase and interphase lymphocytes. Whole blood, obtained from healthy male donors, was exposed in vitro to 0,100,200,300 and 400 cGy of ionizing radiation from a 137 Cs source. Aliquots containing granulocytes and Go lymphocytes from each dose were treated immediately with hypotonic KC1 on ice and harvested. Cells were hybridized with a-and classical satellite probes to the Icen-ql2 region of chromosome 1 and the frequencies of hyperdiploidy and breakage affecting this region were determined. Elevated dose-related frequencies of breakage were detectable hi both lymphocytes and granulocytes immediately following radiation and decreased rapidly over the first 0.25-2 h. In a second series of experiments, the frequencies of hyperdiploidy and breakage for uncultured granulocytes and Go lymphocytes were compared with interphase and metaphase cells following 48-51 h of culture. Similar and significant dose-related increases in breakage were seen for the granulocytes, Go lymphocytes, 48 h cultured interphase and metaphase lymphocytes. A minor increase in hyperdiploidy was seen in the irradiated cultured cells, whereas no hyperdiploid cells were detected in the non-cultured cells. These results indicate that, in general, granulocytes and lymphocytes show similar sensitivity to radiation-induced damage and that cell culture is not required for chromosome breakage to be observed microscopically using this FISH procedure.