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6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A087
To understand the correlation between the three dimensional structure of the
human cell nucleus and the formation of chromosome aberrations induced by
ionizing radiation, simulated cell nuclear models are applied to calculate
relative damage rates (e.g. translocation rates). For this goal the complete
human genome was approximated by polymer chains situated in a spherical
"nuclear" volume which are folded in a territorial or a non-territorial way,
corresponding to different model assumptions. By the comparison with observed
translocation rates of Hiroshima A-bomb survivors, a very good agreement was
obtained with the calculated rates for both territorial and non-territorial
models. Except for one extreme model case, there were no differences in the
relative translocation rates of autosomes between territorial and
non-territorial models. Obiviously, these relative rates depend only on the
effective cross section surface of the chromosomes and the distance of the
damaged chromatin sites. By the modification of one specific territorial
model (Spherical 1Mbp-Chromatin Granule Domain model), the relative
translocation probability for the active and the inactive X-chromosome
(Xi) was determined too. For Xi, a smaller damage probability was predicted
in good agreement with observed results.
INFLUENCE OF IONIZING RADIATION: CALCULATION OF CHROMOSOME ABERRATIONS
APPLYING SIMULATED CELL NUCEAR MODELS
Kreth G 1 2, Münkel Ch 3, Langowski J 3 2, Cremer T 4 2,
Cremer C 1 2
1) Institut für angewandte Physik, Universität Heidelberg
2) Interdisziplinäres Zentrum fuer Wissenschaftliches Rechnen (IWR),
Universitüt Heidelberg (3) Deutsches Krebsforschungszentrum, Heidelberg
(4) Institut für Anthropologie und Humangenetik, Universitüt München,
Germany