Early RNAs in SP82- and SP01-infected Bacillus subtilis may be processed

Transcription of SP82 and SP01 DNAs in vitro by Bacillus subtilis RNA polymerase yielded mostly large RNA species, with many in excess of 1,500 bases in length, whereas most of the RNAs synthesized in vivo early in infection were much smaller. Addition of an extract from uninfected B. subtilis to reaction mixtures containing RNAs synthesized in vitro generated additional discrete RNAs whose mobilities on polyacrylamide gels matched the mobilities of some of the smaller RNAs synthesized in vivo.