W. Martinez-lopez et al., Intrachromosomal localization of aberration breakpoints induced by neutrons and gamma rays in Chinese hamster ovary cells, RADIAT RES, 150(5), 1998, pp. 585-592
Chromosome breakpoints induced by neutrons or gamma rays in Chinese hamster
ovary cells were mapped to Giemsa-light or Giemsa-dark bands or to band ju
nctions. Radiation-induced breakpoints were found to be distributed nonrand
omly according to chromosome or band length. More than 60% of the breakpoin
ts were localized in G-light bands. A group of 13 bands which corresponded
to only 7% of the total chromosome length contained 22% of the breakpoints
produced by neutrons and 14% of those induced by y rays. Seven of these 13
bands are also preferentially damaged by AluI, BamHI and DNase I as reporte
d previously. The results indicate that chromatin and nuclear structure may
play a role in the distribution of breakpoints produced by ionizing radiat
ion and endonucleases. (C) 1998 by Radiation Research Society.