Fig. 3.

The B. subtilis NHEJ system has no measurable effect on spacer acquisition. a S. aureus strain RN4220 carrying the type II-A CRISPR-Cas system on plasmid pRH87 was challenged with phage phiNM4. Spacer acquisition was assessed by PCR on isolated colonies that survived the infection (oligonucleotides are depicted as black arrows). b Adaptation rate measured in the presence of NHEJ, ku, ligD, or GFP carried by plasmids pAB23, pAB24, pAB25, and pAB62, respectively (n = 5, ANOVA, NS P = 0.5674). c Adaptation rate of S. thermophilus DGCC7710 against phage Phi2972 when expressing the B. subtilis NHEJ system from plasmid pAB66 or a control GFP from plasmid pAB69 (n = 3, two-sided t test, NS P = 0.91)