Isolation of a Mammalian Cell Mutant Sensitive to 4-nitroquinoline-1-oxide

Abstract

To clarify the difference between the repair of UV- and 4NQO[4-nitroquinoline-1-oxide]-induced damage in mammalian cells, a 4NQO-sensitive mutant [Q31] was isolated from mouse cells. Mouse lymphoma L5178Y cells were used. The present report describes the isolation of a 4NQO-sensitive mutant of mouse cells, which turned out to be sensitive to UV radiation as well. The mutant is compared to the parental cell line. Isolation of 6 UV-sensitive clones from L5178Y cells has been reported (Kuroki and Miyashita 1976). These clones tended to lose their UV-sensitivity after 2-8 mo. The present mutant Q31 was much more stable, showing the same sensitivity during the 10 mo. following isolation. The findings indicate that the repair pathways of UV- and 4NQO-damage are partly common and partly separate. Q31 and L5178Y cells are equally sensitive to X-rays.