Response from Calms

fusion. We suggest that this fea- ture could be accounted for by the weak suppression that occurs with the 1~2~133 allele2, but that is either absent or less evident for other epi- somal IucZ alleles’ in which revert- ants do not accumulate after plat- ing. The level of suppression of the lucI33 frame shift might be expected to vary from one strain background to another. In fact, in one of the E.