title: Pyrimidine (6-4) pyrimidone photoproduct mapping after sublethal UVC doses: nucleotide resolution using terminal transferase-dependent PCR.
abstract: UVC irradiation of genomic DNA induces two main types of potentially mutagenic base modifications: cyclobutane pyrimidine dimers (CPDs) and the less frequent (15-30% of CPD levels) pyrimidine (6-4) pyrimidone photoproducts (6-4PP). Ligation-mediated PCR (LMPCR), a genomic sequencing technique, allows CPD mapping at nucleotide resolution following irradiation with sublethal doses of UVB or UVC for most cell types. In contrast, a dose of 80 J/m(2) of UVC that is lethal for the majority of cell types is necessary to map 6-4PP by the LMPCR technique. This compromises the use of LMPCR to study the repair of 6-4PP. To date, no other techniques have been developed to study 6-4PP repair at nucleotide resolution. We have therefore adapted a recently developed technique for the mapping of 6-4PP: terminal transferase-dependent PCR (TDPCR). TDPCR is in many ways similar to LMPCR. This technique is more sensitive and allows the mapping of 6-4PP at UVC doses as low as 10 J/m(2) in genomic DNA and in living cells.
authors.affiliation: Division of Pathology, Department of Medical Biology, Université Laval, Quebec, PQ, Canada.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Rochette
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bastien
authors.forename: Takeshi
authors.initials: T
authors.lastname: Todo
authors.forename: Régen
authors.initials: R
authors.lastname: Drouin
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000528:radiation effects; D005347:Fibroblasts / Q000528:radiation effects; D006801:Humans; D009841:Oligonucleotides / Q000737:chemistry / Q000528:radiation effects*; D011743:Pyrimidines / Q000737:chemistry / Q000528:radiation effects*; D011744:Pyrimidinones / Q000737:chemistry / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D009841:Oligonucleotides; D011743:Pyrimidines; D011744:Pyrimidinones; D004247:DNA; C030986:pyrimidine