title: Detection of chromosomal alterations affecting the 1cen-1q12 region in irradiated granulocytes and lymphocytes by multicolour FISH with tandem DNA probes.
abstract: 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 137Cs source. Aliquots containing granulocytes and Go lymphocytes from each dose were treated immediately with hypotonic KCI on ice and harvested. Cells were hybridized with alpha- and classical satellite probes to the 1cen-q12 region of chromosome 1 and the frequencies of hyperdiploidy and breakage affecting this region were determined. Elevated dose-related frequencies of breakage were detectable in 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.
authors.affiliation: Enviromental Toxicology Graduate Program, Department of Entomology, University of California, Riverside 92521, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Rupa
authors.forename: L S
authors.initials: LS
authors.lastname: Hasegawa
authors.forename: D A
authors.initials: DA
authors.lastname: Eastmond
mesh_terms: D002478:Cells, Cultured; D002503:Centromere / Q000235:genetics; D002869:Chromosome Aberrations; D019457:Chromosome Breakage; D002878:Chromosomes, Human, Pair 1; D015342:DNA Probes; D004171:Diploidy; D004307:Dose-Response Relationship, Radiation; D006098:Granulocytes / Q000502:physiology / Q000528:radiation effects*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007399:Interphase / Q000235:genetics / Q000528:radiation effects; D008214:Lymphocytes / Q000502:physiology / Q000528:radiation effects*; D008297:Male; D008677:Metaphase / Q000235:genetics / Q000528:radiation effects; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D015342:DNA Probes