title: The rate of X-ray-induced DNA double-strand break repair in the embryonic mouse brain is unaffected by exposure to 50 Hz magnetic fields.
abstract: OBJECTIVE
  Following in utero exposure to low dose radiation (10-200 mGy), we recently observed a linear induction of DNA double-strand breaks (DSB) and activation of apoptosis in the embryonic neuronal stem/progenitor cell compartment. No significant induction of DSB or apoptosis was observed following exposure to magnetic fields (MF). In the present study, we exploited this in vivo system to examine whether exposure to MF before and after exposure to 100 mGy X-rays impacts upon DSB repair rates.
  
  
  METHODS
  53BP1 foci were quantified following combined exposure to radiation and MF in the embryonic neuronal stem/progenitor cell compartment. Embryos were exposed in utero to 50 Hz MF at 300 μT for 3 h before and up to 9 h after exposure to 100 mGy X-rays. Controls included embryos exposed to MF or X-rays alone plus sham exposures.
  
  
  RESULTS
  Exposure to MF before and after 100 mGy X-rays did not impact upon the rate of DSB repair in the embryonic neuronal stem cell compartment compared to repair rates following radiation exposure alone.
  
  
  CONCLUSIONS
  We conclude that in this sensitive system MF do not exert any significant level of DNA damage and do not impede the repair of X-ray induced damage.
authors: Genome Damage and Stability Centre, Life Sciences, University of Sussex , Brighton.
authors: Lisa
authors: L
authors: Woodbine
authors: Jackie
authors: J
authors: Haines
authors: Margaret
authors: M
authors: Coster
authors: Lara
authors: L
authors: Barazzuol
authors: Elizabeth
authors: E
authors: Ainsbury
authors: Zenon
authors: Z
authors: Sienkiewicz
authors: Penny
authors: P
authors: Jeggo
mesh_terms: D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism* / Q000528:radiation effects*; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000528:radiation effects*; D053595:Embryonic Stem Cells / Q000378:metabolism / Q000528:radiation effects; D005260:Female; D020547:Lateral Ventricles / Q000196:embryology / Q000378:metabolism / Q000528:radiation effects; D060526:Magnetic Fields / Q000009:adverse effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D058953:Neural Stem Cells / Q000378:metabolism / Q000528:radiation effects; D011247:Pregnancy
keywords: DNA double-strand break repair; X-rays; embryonic neuronal stem cells; extremely low frequency magnetic fields (ELF-MF); low dose radiation