dose-response curves were compared for deletions [ colbr ( resistant to colicin b ) mutations being more than 80 % deletions ] and base changes ( reversion of argfam to prototrophy argplus ) induced in the same set of e. coli strains ( wild-type for dna repair , uvra- , pola- and reca- ) by n-methyl-n'-nitro-n-nitrosoguanidine ( ntg ) , ethyl methanesulfonate ( ems ) , hydroxylamine ( ha ) , 4-nitroquinoline i-oxide ( 4nqo ) , mitomycin c ( mtc , uv and x-rays .
C0012899
dna repair
C1419240
reca