Figure 3.

CRISPR interference with M13 phage infection by cells producing unit-sized crRNA through transcription termination. (A). Efficiency of plaquing of wild-type M13 and an escape mutant harboring a C to T substitution at the first position of the g8 protospacer (indicated with a yellow star) on indicated cells is shown. Asterisk or double asterisks show that phages from rare plaques that were formed on tested induced cell lawns contained mutations in the protospacer that rendered CRISPR interference inactive (shown in panel B).