Distribution of radiation-induced exchange aberrations in all human chromosomes.
OBJECTIVE
To investigate the DNA-proportional distribution of radiation-induced chromosome aberrations for all chromosomes of a male and a female human karyotype.


METHODS
Metaphases were prepared from whole blood cultures obtained from two healthy donors and set up after irradiation with 3 Gy 220 kV X-rays. Single whole-chromosome FISH painting simultaneously with pancentromeric DNA painting were performed separately for each chromosome of the human karyotype. One thousand exclusively first-division metaphases were analysed per chromosome and donor. After statistical analysis, the data obtained were compared with theoretically expected values.


RESULTS
All aberration types (translocations, dicentrics) showed deviations from a DNA-proportional distribution. For both donors, chromosomes 2 and 3 exhibited significantly less and chromosome 4 more symmetrical translocations than expected. Chromosomes 15 and 22 showed more symmetrical translocations than predicted for one of the two donors. Less dicentrics than expected became apparent for chromosomes 2, 3 and 18, while more dicentrics were seen for chromosomes 15, 16 and 17. Moreover, chromosomes 4, 14 and 22 showed a significant deviation from the theoretically expected 1:1 ratio of the yields of symmetrical translocations to the yields of dicentrics.


CONCLUSIONS
The results from the whole-chromosome complement in two different donors confirmed published data from the analysis of single chromosomes that some human chromosomes were not involved in radiation-induced dicentrics and symmetrical translocations proportional to their DNA content. This must be taken into account if chromosome subsets for dose reconstruction are selected or if whole genomic frequencies have to be calculated from partial genome analysis.
Braselmann
H
H
National Research Center for Environment and Health, Institute of Molecular Radiobiology, D-85764 Neuherberg, Germany. braselm@gsf.de
Kulka
U
U
Huber
R
R
Figel
H M
HM
Zitzelsberger
H
H
D000328:Adult; D002869:Chromosome Aberrations; D002877:Chromosomes, Human / Q000528:radiation effects*; D004249:DNA Damage; D005260:Female; D015894:Genome, Human; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D008677:Metaphase / Q000528:radiation effects; D015233:Models, Statistical; D012737:Sex Factors