Use of multicolour chromosome painting to identify chromosomal rearrangements in human lymphocytes exposed to bleomycin: A comparison with conventional cytogenetic analysis of giemsa‐stained chromosomes

Abstract

Exchange aberrations induced by bleomycin were identified by multicolour fluorescence in situ hybridisation (FISH) with probes for chromosomes 1, 2, and 3. The frequency and distribution of aberration types were compared to conventional metaphase analysis of Giemsa-stained chromosomes from the same human lymphocyte cultures. The total percentage of exchanges detectable by painting three pairs of chromosomes with separate colours was calculated as 40%. Giemsa staining revealed predominantly asymmetric chromosome exchanges, which are expected to comprise 50% of the total induced exchanges. Genomic exchange frequencies were, therefore, determined by multiplying the observed frequencies from FISH analysis by 2.5 and the number of asymmetric exchanges identified in Giemsa-stained slides by 2.0. By these calculations, the genomic exchange frequency calculated from chromosome painting exceeded that estimated by Giemsa-staining. This difference was due to the identification by chromosome painting of a unique class of cells in which chromosomes had undergone complex exchanges (nonreciprocal exchanges involving multiple mutual sites). The percentage of cells exhibiting exchanges was similar for both methods.

Analysis by FISH of the spectrum of chromosome aberrations induced by X-rays in G0 human lymphocytes and their fate through mitotic divisions in culture

“…In contrast to our findings, Ellard et al [1995] reported that FISH gave a higher estimate of the genomic frequency of chromosome aberrations induced by bleomycin in human lymphocytes than that obtained by conventional scoring of Giemsa-stained chromosomes. They attributed the difference to the detection by FISH of many complex nonreciprocal exchanges.…”

“…For example, Kovacs et al [1994] found no difference in their frequencies in chromosome 4 painted by FISH in human fibroblasts. However, translocation/dicentric (t/ dic) ratios greater than 1.00 have been reported in many other studies using FISH: 1.6 -2.4 [Lucas et al, 1989], 1.5-2.0 [Natarajan et al, 1992], 1.8 [Schmid et al, 1992], 1.5 [Nakano et al, 1993], 1.4 -1.8 [Tucker et al, 1993b], 1.48 [Knehr et al, 1994], 1.15 [Ellard et al, 1995], and 1.13 [Stephan and Pressl, 1997]. Some studies report X-rayinduced translocation:dicentric ratios just marginally greater than the theoretical 1:1.…”

“…Besides the possibility of an actual difference in the frequencies at which these two classes of aberrations are formed, experimental factors may contribute to a t/dic ratio greater than 1.00 Ellard et al, 1995]. Translocations may be overestimated by misclassification of some dicentrics as translocations in FISH scoring, inclusion of second-division cells among the cells scored, and inclu-sion of spontaneous translocations (which outnumber spontaneous dicentrics) at low dosages.…”

Analysis of streptonigrin‐induced incomplete chromosome elements and interstitial fragments in Chinese hamster cells using a telomeric PNA probe

“…SN gave linear concentration-response curves for induction of most of the asymmetrical chromosomal aberrations (the only exception were ring chromosomes). Similar find- ings using FISH have been reported for bleomycin [Ellard et al, 1995;Puerto et al, 1999;Bolzán and Bianchi, 2004] and high LET radiation (neutrons) [Boei et al, 2001]. In contrast, low LET radiation produces linear-quadratic responses [Boei et al, , 2001.…”

The Importance of Age and Smoking in Evaluating Adverse Cytogenetic Effects of Exposure to Environmental Agents

“…Numerous laboratories have shown that chromosome painting is a valid method of quantifying chromosome rearrangements (1)(2)(3)(4)(5)(6)(7), with the result that painting is now widely used for measuring chromosome damage. Painting is especially useful for evaluating exposures that occurred many years previously because of the speed and accuracy with which stable aberrations (translocations and insertions) can be enumerated.…”