Transfection of the cloned human excision repair gene ERCC-1 to UV-sensitive CHO mutants only corrects the repair defect in complementation group 2 mutants.
The human DNA-excision repair gene ERCC-1 is cloned by its ability to correct the excision-repair defect of the ultraviolet light- and mitomycin-C-sensitive CHO mutant cell line 43-3B. This mutant is assigned to complementation group 2 of the excision-repair-deficient CHO mutants. In order to establish whether the correction by ERCC-1 is confined to CHO mutants of one complementation group, the cloned repair gene, present on cosmid 43-34, was transfected to representative cell lines of the 6 complementation groups that have been identified to date. Following transfection, mycophenolic acid was used to select for transferants expressing the dominant marker gene Ecogpt, also present on cosmid 43-34. Cotransfer of the ERCC-1 gene was shown by Southern blot analysis of DNA from pooled (500-2000 independent colonies) transformants of each mutant. UV survival and UV-induced UDS showed that only mutants belonging to complementation group 2 and no mutants of other groups were corrected by the ERCC-1 gene. This demonstrates that ERCC-1 does not provide an aspecific bypass of excision-repair defects in CHO mutants and supports the assumption that the complementation analysis is based on mutations in different repair genes.
|Keywords||*DNA Repair, *Genes, Structural/radiation effects, *Genetic Complementation Test, *Mutation, *Transfection, 0 (Cosmids), Animals, Cell Line, Cloning, Molecular, Cosmids, Cricetulus, DNA Replication/radiation effects, Hamsters, Human, Support, Non-U.S. Gov't, Support, U.S. Gov't, Non-P.H.S., Ultraviolet Rays|
van Duin, M., Janssen, J.H., de Wit, J., Hoeijmakers, J.H.J., Thompson, L.H., Bootsma, D., & Westerveld, A.. (1988). Transfection of the cloned human excision repair gene ERCC-1 to UV-sensitive CHO mutants only corrects the repair defect in complementation group 2 mutants.. Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis, 193, 123–130. Retrieved from http://hdl.handle.net/1765/2998