Radiation-induced cytogenetic damage in relation to changes in interphase chromosome conformation

Journal Article · Sat Mar 01 04:00:00 EST 1986 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576690· OSTI ID:5617087

Pantelias, G E

The premature chromosome condensation (PCC) technique was used to study several factors that determine the yield of chromosome fragments as observed in interphase cells after irradiation. In addition to absorbed dose and the extent of chromosome condensation at the time of irradiation, changes in chromosome conformation as cells progressed through the cell cycle after irradiation affected dramatically the yield of chromosome fragments observed. As a test of the effect of chromosome decondensation, irradiated metaphase Chinese hamster ovary (CHO) cells were allowed to divide, and the prematurely condensed chromosomes in the daughter cells were analyzed in their G1 phase. The yield of chromosome fragments increased as the daughter cells progressed toward S phase and chromosome decondensation occurred. When early G1 CHO cells were irradiated and analyzed at later times in G1 phase, an increase in chromosome fragmentation again followed the gradual increase in chromosome decondensation. As a test of the effect of chromosome condensation, G0 human lymphocytes were irradiated and analyzed at various times after fusion with mitotic CHO cells, i.e., as condensation proceeded. The yield of fragments observed was directly related to the amount of chromosome condensation allowed to take place after irradiation and inversely related to the extent of chromosome condensation at the time of irradiation. It can be concluded that changes in chromosome conformation interfered with rejoining processes. In contrast, resting chromosomes (as in G0 lymphocytes irradiated before fusion) showed efficient rejoining. These results support the hypothesis that cytogenetic lesions become observable chromosome breaks when chromosome condensation or decondensation occurs during the cell cycle.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 5617087
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RADIATION EFFECTS
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CYCLE
CHO CELLS
CHROMOSOMAL ABERRATIONS
CHROMOSOMES
CONNECTIVE TISSUE CELLS
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
HAMSTERS
IN VITRO
LEUKOCYTES
LYMPHOCYTES
MAMMALS
MATERIALS
MUTATIONS
RADIATION EFFECTS
RODENTS
SOMATIC CELLS
VERTEBRATES