Hamster origin of multiple chromosome rearrangements in first cleavage human-hamster embryos

Abstracts / Mutation Research 360 (1996) 201-300

variety of spots representing a number of aromatic DNA adducts. Adduct levels in heart tissue of cigarette smokers (mean +_ SE: 8.8 +_ 1.5 adducts per 10 s nucleotides, n = 13)were significantly enhanced compared with former smokers (4.3 + 0.9, n = 15; p = 0.002) and non-smokers (3.0 +_ 1.0, n = 11 ; p = 0.002). In the smokers group a linear relationship was observed between adduct levels and daily cigarette smoking ( r = 0.54; p = 0.05). Our results suggest that smoking-related DNA damage in heart may be pathogenetically associated with cardiovascular diseases, parallel to the association of DNA damage and lung cancer in smokers. 5-1

Hamster origin of multiple chromosome rearrangements in first cleavage humanhamster embryos R. Alvarez a, L. Tusell a, A. Genesch a, R. Mir6 a, M.R. Caballfn b, j. Benet a j. Egozcue a; a Departament de Biologia Animal, Biologia Vegetal i Ecologia, b Departament de Biologia Cellular i Fisiologia, Universitat Autbnoma de Barcelona, E-08193 Bellaterra, Spain, Metaphases showing multiple rearrangements are sporadically obtained when using the human-hamster fertilization system to analyze human sperm chromosomes. It had been suggested that in in vivo irradiated patients, first cleavage metaphases with multiple aberrations appeared as a short-term effect of radiotherapy. We studied the origin of 45 first cleavage metaphases with multiple chromatid exchanges and fragmented chromosomes using fluorescent in situ hybridization techniques (FISH) with either human or hamster genomic DNA probes. Using the human genomic DNA probe, 25 metaphases with multiple rearrangements were analyzed. Under the fluorescence microscope, all of them showed the red background of propidium iodide-stained bulk DNA, demonstrating that no hybridization had occurred, and that they were not of human origin. The other 20 metaphases with multi-

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pie rearrangements, were hybridized with the total hamster DNA probe. All of them showed the typical yellow staining of the fluorescein labelled probe, demonstrating that hybridization with total hamster DNA had taken place. Our study demonstrates that all these metaphases hybridize with hamster genomic DNA probes and not with human DNA, proving their hamster origin. 5-2

Comparison of radiation-induced chromosome aberrations in mouse splenocytes and differentiating type spermatogonia D. Benova, I. Georgieva, T. Nikolova, M. Grigorova, M. Bulanova, I. Rupova, R. Christova, A. Yagova, R. Kucheva; National Centre of Radiobiology and Radiation Protection, Sofia, Bulgaria An experiment sponsored by the Commission of the European Communities was undertaken to compare the yield of chromosome aberrations in splenocytes and differentiating type spermatogonia in mice irradiated with 0.5, 1.0, 2.0 and 3.0 Gy I37Cs gammarays. The chromosome aberrations in splenocytes cultured in vitro increase with the dose. At 26th hour after irradiation only the chromosome type fragments increase with the dose in the differentiating spermatogonia. The level of the dicentrics is much less than in splenocytes and did not change with the dose. 5-3

Application of novel chromosome DNA probes in the detection of aneuploidy in rat fibroblasts and epididymal sperm J.M. de Stoppelaar a, X. Lowe b, A.J. Wyrobek b, j. Bishop c, G.R. Mohn ~ and B. Hoebee a; , Laboratory of Carcinogenesis and Mutagenesis, National Institute of Public Health and Environmental Protection, Bilthoven, the Netherlands, b Lawrence Livermore National Laboratory, Livermore, CA, USA,