Induction and persistence of pyrimidine dimers in the epidermal DNA of two strains of hairless mice.
The ultraviolet-light induction of DNA damage has been measured in the epidermis of hairless mice with the use of damage-specific endonucleases from Micrococcus luteus. The rates of induction of endonuclease-sensitive sites in HRS/J/Anl and Skh:hairless-1 mice were 6.1 +/- 0.5 X 10(-11) and 6.5 +/- 0.8 X 10(-11)/dalton/J/sq m from a FS40 fluorescent sun lamp (280 to 400 nm), respectively. Enzymatic photoreactivation with yeast photoreactivating enzyme showed that approximately 80% of the endonuclease-sensitive sites were cycloburyl pyrimidine dimers. In both strains of mice the pyrimidine dimers remained in high-molecular-weight DNA for 24 hr after irradiation. These data show that mouse epithelial cells in vivo have little or no capacity for the excision repair of pyrimidine dimers.
D000818:Animals; D046508:Culture Techniques; D004247:DNA / Q000378:metabolism* / Q000528:radiation effects; D004260:DNA Repair; D005260:Female; D051379:Mice; D008819:Mice, Nude; D011118:Polynucleotide Ligases / Q000378:metabolism; D011740:Pyrimidine Dimers / Q000378:metabolism* / Q000528:radiation effects; D012867:Skin / Q000378:metabolism* / Q000528:radiation effects; D013045:Species Specificity; D014466:Ultraviolet Rays
D011740:Pyrimidine Dimers; D004247:DNA; D011118:Polynucleotide Ligases