Radiation-induced chromosomal aberrations in mouse 10T1/2 cells: dependence on the cell-cycle stage at the time of irradiation.
Cell-cycle stage radiosensitivity for the induction of chromosome aberrations has been investigated in C3H 10T1/2 cells. Exponentially growing cells were irradiated with 3 Gy X-rays (80 kVp) or 0.6 Gy alpha-particles (LET = 101 keV/micron). The two doses produce the same survival level (37%) in the asynchronous population. Cells were harvested at four different times following irradiation and cell-cycle phase at the time of irradiation was assessed by using the differential replication staining technique. The frequency of chromosome aberrations produced in a given stage of the cell cycle was not constant as a function of the sampling time, but this could not be simply related to the existence of subphases exhibiting different radiosensitivity, because of cell-cycle perturbation introduced by radiation. X-radiation induced more exchanges than deletions, whereas a predominance of isochromatid deletions was observed after alpha-irradiation. This can be interpreted on the basis of the different patterns of energy deposition of densely- and sparsely-ionizing radiation. Both X- and alpha-rays produced a significant increase in the frequency of Robertsonian translocations when cells were exposed in G1 or S phase, but not in G2 phase.
Durante
M
M
Dipartimento di Scienze Fisiche, Università di Napoli Federico II, Italy.
Gialanella
G
G
Grossi
G F
GF
Nappo
M
M
Pugliese
M
M
Bettega
D
D
Calzolari
P
P
Chiorda
G N
GN
Ottolenghi
A
A
Tallone-Lombardi
L
L
D000512:Alpha Particles; D000818:Animals; D002453:Cell Cycle / Q000502:physiology / Q000528:radiation effects; D002478:Cells, Cultured; D002842:Chromatids / Q000528:radiation effects; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000528:radiation effects*; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects*; D016193:G1 Phase / Q000502:physiology; D016195:G2 Phase / Q000502:physiology; D051379:Mice; D008809:Mice, Inbred C3H; D008940:Mitotic Index / Q000528:radiation effects; D008954:Models, Biological; D011836:Radiation Tolerance; D016196:S Phase / Q000502:physiology