Neutron Energy-Dependent Initial DNA Damage and Chromosomal Exchange.

Neutron energy-dependent initial DNA damage and chromosomal exchange.

This study was undertaken to investigate the biological effect of monoenergetic neutrons on human lymphocyte DNA and chromosomes. Monoenergetic neutrons of 2.3, 1.0, 0.79, 0.57, 0.37 and 0.186 MeV were generated, and 252Cf neutrons and 60Co gamma-rays were also used for comparison. Biological effect was evaluated two ways. The RBE values with the comet assay were estimated as 6.3 and 5.4 at 0.3...

Impact of DNA Damage on the Frequency of Sperm Chromosomal Aneuploidy in Normal and Subfertile Men

Background: Various frequencies of sperm aneuploidy are reported in sperms of subfertile patients compared to normal individuals. Moreover, sperm DNA damage is shown to be associated with male infertility. In this study, the rate of DNA damage and frequencies of aneuploidy in sperms of subfertile patients was investigated. Methods: Semen samples were obtained from healthy normal and subfertile ...

DNA replication meets genetic exchange: chromosomal damage and its repair by homologous recombination.

Proceedings of the National Academy of Sciences Colloquium on the roles of homologous recombination in DNA replication are summarized. Current findings in experimental systems ranging from bacteriophages to mammalian cell lines substantiate the idea that homologous recombination is a system supporting DNA replication when either the template DNA is damaged or the replication machinery malfuncti...

Reconstitution of an ATM-dependent checkpoint that inhibits chromosomal DNA replication following DNA damage.

Cell cycle checkpoints lead to the inhibition of cell cycle progression following DNA damage. A cell-free system derived from Xenopus eggs has been established that reconstitutes the checkpoint pathway inhibiting DNA replication initiation. DNA containing double-strand breaks inhibits replication initiation in a dose-dependent manner. Upon checkpoint activation, a prereplicative complex is asse...

Radiation track and DNA damage