DNA-proportional distribution of radiation-induced chromosome aberrations analysed by fluorescence in situ hybridization painting of all chromosomes of a human female karyotype.
OBJECTIVE
This is the extension of a previous study, showing deviations from a DNA-proportional involvement of 12 single chromosomes (1-4, 6-10, 12, 14 and X) in radiation-induced translocations and dicentrics measured by FISH-painting and classified by standard cytogenetic scoring criteria. By adding data on chromosomes 2, 4, 5, 9, 11-13, 15-22 and X the analysis now comprises all chromosomes of a human female karyotype evaluated with three nomenclature systems (PAINT, S & S and a conventional method).


METHODS
Metaphase spreads were prepared from lymphocytes irradiated with 3 Gy 220 kV X-rays. FISH painting was performed with single chromosome-specific probes in combination with a pancentromeric probe.


RESULTS
Deviations from a DNA-proportional distribution became apparent for all aberration parameters analysed with the three nomenclature systems. Chromosomes 2, 3 and 6 were less frequently involved and chromosomes 16, 17 and 20 were more frequently involved in exchange aberrations. Generally, smaller chromosomes (15-22, with the exception of chromosome 19) were more frequently involved in aberration formation than expected.


CONCLUSIONS
The assumption that the probability of a chromosome being involved in an exchange aberration is proportional to its DNA content is not supported by the present data.
Barquinero
J F
JF
Universitat Autònoma de Barcelona, Unitat d'Antropologia, Dpt. Biologia Animal, Biologia Vegetal i Ecologia, Facultat de Ciències, Bellaterra, Spain.
Knehr
S
S
Braselmann
H
H
Figel
M
M
Bauchinger
M
M
D002452:Cell Count; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007621:Karyotyping; D008214:Lymphocytes / Q000528:radiation effects*; D008677:Metaphase; D009626:Terminology as Topic; D014178:Translocation, Genetic