Equivalence of UDS responses for established cell lines and primary cells derived from the mei-9a and mus201D1 excision repair-deficient strains of Drosophila melanogaster

Autoradiographic analysis of unscheduled DNA synthesis in response to DNA damage produced by relatively high doses of the direct-acting, monofunctional alkylating agent, MMS, (4.5 mM) and UV (40 J/m²) demonstrates that established cell lines, derived from the mei-9^a and mus201^D1 excision repair-deficient strains of Drosophila melanogaster, perform no measurable incorporation of [³H]thymidine into repair patches, in accordance with the observations made for the corresponding primary embryonic cells derived from the two mutagen-sensitive strains of flies. These established cell lines can therefore be used as appropriate models for both examination of the biochemical basis of the genetic defects in the mei-9 and mus201 mutations and the role of excision-repair processes in spontaneous and induced mutation induction in eukaryotic cells.