Molecular analysis of gamma-ray-induced mutations at the hprt locus in primary human skin fibroblasts by multiplex polymerase chain reaction.

A total of 153 hprt mutants (23 spontaneous, 130 gamma-ray-induced) of primary human skin fibroblasts were isolated and genetic alterations at the locus were studied by multiplex polymerase chain reaction (PCR). The analyses showed that 51% (66/130) of gamma-ray-induced genetic changes were large deletions, whereas the majority of spontaneous mutants (21/23) exhibited point mutations. The spectrum of large genetic alterations appeared to be dependent on dose in gamma-ray-induced (1-4 Gy) mutations; mutants with complete loss of the hprt locus comprised 21 (3/14) or 39% (15/38) of clones isolated after irradiation with 1 or 4 Gy, respectively.

Mutations induced by ionizing radiation in a plasmid replicated in human cells. II. Sequence analysis of alpha-particle-induced point mutations.

The human shuttle plasmid pZ189, containing the Escherichia coli supF gene as the mutational target, was irradiated in vitro with 210Po alpha particles and transfected into human lymphoblastoid cells. Plasmids which were replicated in human cells were recovered and those containing mutant supF genes were isolated by phenotypic screening in E. coli.

Mutations induced by ionizing radiation in a plasmid replicated in human cells. I. Similar, nonrandom distribution of mutations in unirradiated and X-irradiated DNA.

The Escherichia coli supF gene encoding the suppressor tyrosine tRNA in a human shuttle plasmid, pZ189, was used as a target for molecular analysis of X-ray-induced mutations in human lymphoblastoid cells. Following replication of the in vitro-irradiated plasmid in human cells, the mutant supF-containing molecules were cloned by phenotypic screening in E. coli and the nature of the mutations was determined by direct sequencing of the tRNA gene.

Organization of DNA in cerebellar neurons of ageing unirradiated and irradiated rats.

Male Fischer 344 rats were either unirradiated or whole-brain irradiated with single doses of 10.83 or 17.16 Gy of X-rays at 4 months of age, and the organization of the DNA in permanently non-dividing cerebellar neurons examined as a function of age, dose and time after irradiation.

Alterations of neuronal nuclear matrix and chromatin structure after irradiation under aerobic and anoxic conditions.

This study was undertaken to determine if structural alterations of the bulk chromatin and the amount of protein associated with the nuclear matrix in cerebellar neurons depend on radiation dose and a cell's state of oxygenation. After irradiation with 2.5 to 25.