The LET dependence of interphase chromosome breakage and rejoining in two mammalian cell lines
Chromosomal breakage and rejoining was examined in the G{sub 1}-phase of a Chinese hamster ovary (CHO-tsH1) cell line using a technique known as premature chromosome condensation. The initial level of breakage was measured in cells exposed to x-rays and 9 particle beams covering a LET range of more than 3 orders of magnitude. The rate and extent of rejoining of interphase chromosome breaks was measured in cells exposed to 4 particle beams having LET values from 0.56 to 183 keV/{mu}m. Cell survival dose-response curves were obtained for x-rays and 4 particle beams having LET values in the range of 1.5 to 2700 keV/{mu}m. The average number of chromosome breaks per particle traversal of the cell nucleus rose steadily from {approximately}0.006 to 11 breaks/cell as the LET increased from 0.56 to 2700 keV/{mu}m. Chromosome breaks were Poisson distributed within the G{sub 1}-phase cell population after exposure to low LET radiations. The rate of rejoining of interphase chromosome breaks showed no clear LET dependence. However the proportion of apparently nonrejoining breaks was observed to be LET-dependent, increasing nearly 4-fold as the LET rose from 0.56 to 183 keV/{mu}m. Experiments were also conducted with a human/hamster hybrid cell line, UV24C2-3, exposed to x-rays and a Neon-ion particle beam.
- Research Organization:
- California Univ., Berkeley, CA (USA)
- OSTI ID:
- 6973804
- Country of Publication:
- United States
- Language:
- English
Similar Records
Chromosomal damage and repair in G{sub 1}-phase Chinese hamster ovary cells exposed to charged-particle beams
Kinetics of chromosome rejoining in normal human fibroblasts after exposure to low- and high-LET radiations
Related Subjects
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CHO CELLS
CHROMOSOMAL ABERRATIONS
DNA REPAIR
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
ENERGY TRANSFER
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
IONIZING RADIATIONS
LET
MAMMALS
MAN
MUTATIONS
PRIMATES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RBE
RECOVERY
REPAIR
SURVIVAL TIME
VERTEBRATES
X RADIATION