Involvement of G sub(2)-dependent DNA double-strand break repair in the formation of ultraviolet light B-induced chromosomal aberrations

摘要

Wortmannin, an inhibitor of DNA double-strand break (DSB) repair added 19 h before harvest enhanced the incidence of ultraviolet light B (UVB)-induced chromatid aberrations in Chinese hamster V79 cells. Posttreatment with wortmannin for last 3 h of culture also enhanced the yield of breakage-type chromatid aberrations and suppressed the yield of exchange-type chromatid aberrations almost completely. Thus, the inhibition of DSB repair in the G sub(2) phase stimulated the breakage-type aberration formation, while suppressing the exchange-type aberration formation. We propose the model of UVB-induced chromatid-type aberration formation which might be fully related to G sub(2)-dependent DSB repair pathway.