The kinetics of postirradiation chromatin restitution as revealed by chromosome aberrations detected by premature chromosome condensation and fluorescence in situ hybridization.

In a study of X-ray-induced chromosome aberrations in human G(0) lymphocytes irradiated with 4 Gy using premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH), the time-dependent pattern of chromosome fragments and interchromosomal exchanges involving chromosome 4 was recorded after postirradiation incubation times varying from 0.5 to 46.5 h.

Chromosome aberrations induced in human lymphocytes by 3.45 MeV alpha particles analyzed by premature chromosome condensation.

Premature chromosome condensation (PCC) experiments using human lymphocytes with centromere staining have shown that after exposure to 3.45 MeV alpha-particle radiation, the full number of dicentric chromosomes appears when the cell fusion protocol is applied immediately after irradiation. In this case, the time available for repair and misrepair of DNA damage is only about 30 min.

Kinetics of the formation of chromosome aberrations in X-irradiated human lymphocytes: analysis by premature chromosome condensation with delayed fusion.

Human lymphocytes irradiated with graded doses of up to 5 Gy of 150 kV X rays were fused with mitotic CHO cells after delay times ranging from 0 to 14 h after irradiation. The yields of dicentrics seen under PCC conditions, using C-banding for centromere detection, and of excess acentric fragments observed in the PCC experiment were determined by image analysis. At 4 Gy the time course of the yield of dicentrics shows an early plateau for delay times up to 2 h, then an S-shaped rise and a final plateau which is reached after a delay time of about 8 to 10 h.

Characterization and mapping of a highly conserved processed pseudogene and an intron-carrying gene of the heat shock cognate protein 70 (Hsc70) gene family in the rat.

A processed pseudogene of the rat Hsc70 gene, Hsc70-ps1, is described, which still presents the open reading frame of the original gene. The pseudogene does not appear to be expressed. It maps to rat Chromosome (Chr) 2.