Premium
R ogerio M eneghini
Author(s) -
Menck Carlos F. M.
Publication year - 1982
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.1751-1097.1982.tb02601.x
Subject(s) - micrococcus luteus , pyrimidine dimer , chemistry , dna , cell culture , microbiology and biotechnology , endonuclease , biophysics , biology , dna damage , biochemistry , escherichia coli , genetics , gene
— Mouse cells (3T3 line) and human fibroblasts are equally sensitive to UV light. At fluences of 2.0–2.5 J/m 2 mouse cells excise only 20% of the pyrimidine dimers as compared to 80% excised by human fibroblasts. This fluence allows 37% survival in both cases. Hence, mouse cells are more resistant to the same burden of unexcised dimers. The reason for this increased tolerance to dimers does not seem to be due to a recombinational mechanism, as judged by the fact that only ca. 5% of the dimers are transferred from parental to daughter strands. The transfer of dimers was measured by the Micrococcus luteus UV endonuclease assay, irradiating cells at Gi to avoid artifacts arising from introduction of dimers in nascent strands. The possibility of other mechanisms being involved in the process of tolerance to DNA lesions is discussed.