title: Bromodeoxyuridine does not contribute to sister chromatid exchange events in normal or Bloom syndrome cells.
abstract: Sister chromatid exchanges (SCEs) are considered sensitive indicators of genome instability. Detection of SCEs typically requires cells to incorporate bromodeoxyuridine (BrdU) during two rounds of DNA synthesis. Previous studies have suggested that SCEs are induced by DNA replication over BrdU-substituted DNA and that BrdU incorporation alone could be responsible for the high number of SCE events observed in cells from patients with Bloom syndrome (BS), a rare genetic disorder characterized by marked genome instability and high SCE frequency. Here we show using Strand-seq, a single cell DNA template strand sequencing technique, that the presence of variable BrdU concentrations in the cell culture medium and in DNA template strands has no effect on SCE frequency in either normal or BS cells. We conclude that BrdU does not induce SCEs and that SCEs detected in either normal or BS cells reflect DNA repair events that occur spontaneously.
authors.affiliation: European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands.
authors.forename: Niek
authors.initials: N
authors.lastname: van Wietmarschen
authors.affiliation: European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands Terry Fox Laboratory, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada Division of Hematology, Department of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada p.m.lansdorp@umcg.nl.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Lansdorp
mesh_terms: D001816:Bloom Syndrome / Q000378:metabolism* / Q000473:pathology*; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D013698:Templates, Genetic
chemical_list: D004247:DNA; D001973:Bromodeoxyuridine