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Biological dosimetry by interphase chromosome painting
M Durante1, K George, T C Yang
1Radiation Biology Laboratory, National Aeronautics and Space Administration (NASA), Lyndon B. Johnson Space Center, Houston, Texas 77058, USA.
Radiation Research
|January 1, 1996
Summary
This study combined chromosome painting and premature chromosome condensation for radiation biodosimetry. Painted interphase chromosomes offer a feasible method for estimating radiation dose, especially when samples are processed quickly.
Area of Science:
- Radiation Biology
- Cytogenetics
- Biodosimetry
Background:
- Traditional methods for lymphocyte radiation biodosimetry include fluorescence in situ hybridization (FISH) of metaphase spreads and premature chromosome condensation (PCC) in interphase nuclei.
- These methods have limitations in terms of sample processing time and the type of chromosomal aberrations analyzed.
Purpose of the Study:
- To evaluate the feasibility of using painted interphase chromosomes, derived from PCC, for biological dosimetry.
- To compare the dose-response curves of chromosomal aberrations in interphase versus metaphase chromosomes after gamma irradiation.
Main Methods:
- Human peripheral lymphocytes were exposed to gamma rays and fused with mitotic Chinese hamster cells immediately or 8 hours post-irradiation.
- Prematurely condensed interphase chromosomes and metaphase chromosomes were analyzed using FISH with whole-chromosome probes specific for human chromosomes 3 and 4.
- Dose-response curves for chromosomal fragment induction and interchanges were established.
Main Results:
- Immediately after irradiation, a linear dose-response for fragment induction in interphase chromosomes was observed, reflecting genome-wide breakage.
- Eight hours post-irradiation, a linear-quadratic dose-response for chromosome interchanges, the predominant aberration in interphase PCC, was similar to that seen in metaphase chromosomes.
- Painted interphase chromosomes provide reliable biodosimetry data.
Conclusions:
- Painting prematurely condensed chromosomes is a viable technique for biological dosimetry.
- This method is particularly useful when blood samples are available shortly after radiation exposure or when interphase cells are preferred for scoring over mitotic cells.