Decline of growth rate with age should be absent under benign conditions, or where present, minimal and due to the small amounts of damage that cannot be efficiently repaired whilst segregating passively, due to stochastic rather than active mechanisms.
XRCC3 (x-ray repair cross-complementation group 3) allows double strand breaks to be efficiently repaired via the homologous recombination repair pathway, for correct chromosomal segregation and of DNA cross links repair [ 3, 10].
However, despite the involvement of lamins A/C in nesprin-2/ERK compartmentalisation, lamins A/C depletion did not impair, ATM or Chk2 phosphorylation and DNA damage continued to be efficiently repaired.
We showed that the double-strand DNA breaks mediated by I- SceI can be efficiently repaired when an exogenous DNA cassette flanked by regions homologous to the I- SceI landing locus was added during transformation.
However, the kinetics of the recovery of DNA breaks of radio-contaminated Chernobyl samples revealed that lesions were efficiently repaired at the stage of cotyledon.
Finally, like in HPGS, DSBs formed in normal human aging also are unrepairable although genotoxin-induced DSBs in the same cells can be efficiently repaired [ 2].
Under normal conditions, SSBs are efficiently repaired and do not lead to significant cell death.
However, while oxidative damage to DNA, proteins and lipids indeed occurs commonly in vivo, most such damage is efficiently repaired and, consequently, steady state levels of such damage in healthy individuals are usually low [11].
Upon binding to the target sequence, a functional nuclease is reconstituted that creates double-stranded breaks in the DNA that are efficiently repaired by non-homologous end joining.
Whereas transfected plasmid DNA containing either a U G mispair or U A base pairs was efficiently repaired in the control lines, uracil-DNA repair was not evident in the lines producing Ugi.
