Multiple pathways of DNA double-strand break processing in a mutant Indian muntjac cell line.
DNA break processing is compared in the Indian muntjac cell lines, SVM and DM. The initial frequencies and resealing of X-ray generated single- and double-strand breaks are similar in the two cell lines. Inhibiting the repair of UV damage leads to greater double-strand breakage in SVM than in DM, and some of these breaks are not repaired; however, repair-associated single-strand breakage and resealing are normal. Dimethylsulfate also induces excess double-strand breakage in SVM, and these breaks are irreparable. Restricted plasmids are reconstituted correctly in SVM at approximately 30% of the frequency observed in DM. Thus SVM has a reduced capacity to repair certain types of double-strand break. This defect is not due to a DNA ligase deficiency. We conclude that DNA double-strand breaks are repaired by a variety of pathways within mammalian cells and that the structure of the break or its mode of formation determines its subsequent fate.
Bouffler
S D
SD
Department of Zoology, University of Cambridge, U.K.
Jha
B
B
Johnson
R T
RT
D000818:Animals; D002460:Cell Line; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair / Q000235:genetics*; D004262:DNA Restriction Enzymes; D003670:Deer / Q000235:genetics*; D015698:Genomic Library; D008297:Male; D009154:Mutation; D010957:Plasmids; D014162:Transfection; D014466:Ultraviolet Rays
D004247:DNA; D004262:DNA Restriction Enzymes