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EXCISION REPAIR OF UVR‐INDUCED PYRIMIDINE DIMERS IN CORNEAL DNA
Author(s) -
Freeman Steven E.,
Applegate Lee A.,
Ley Ronald D.
Publication year - 1988
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1988.tb02707.x
Subject(s) - pyrimidine dimer , microbiology and biotechnology , dna , agarose gel electrophoresis , biology , nucleotide excision repair , dna damage , micrococcus luteus , endonuclease , pyrimidine , in vivo , chemistry , biochemistry , genetics , gene , escherichia coli
— We measured excision repair of ultraviolet radiation (UVR)‐induced pyrimidine dimers in DNA of the corneal epithelium of the marsupial, Monodelphis domestica , using damage‐specific nucleases from Micrococcus luteus in conjunction with agarose gel electrophoresis. We observed that 100 J ‐2 of UVR from aFS–40 sunlamp(280–400 nm) induced an average of 2.2 ± 0.2 times 10 ‐2 endonuclease‐sensitive sites per kilobase (ESS/kb) (pyrimidine dimers) and that ∼ 50% of the dimers were repaired within 12 h after exposure. We also determined that an exposure of 400 J m ‐2 was needed to induce comparable numbers of pyrimidine dimers (2.5 times 10 ‐2 ) in the DNA of skin of M. domestica in vivo . In addition, we found that 50% of the dimers were also removed from the epidermal cells of M. domestica within 12 h after exposure. A dose of 100 J m ‐2 was necessary to induce similar levels of pyrimidine dimers (2.0 ± 0.2 times 10 ‐2 ) in the DNA of the cultured marsupial cell line Pt K2 ( Potorous tridactylus ).