Fig. 3
From: A rapid and versatile tool for genomic engineering in Lactococcus lactis
Application and improvement of CRISPR/Cas9 system in L. lactis NZ9000. a The nucleotide sequences of protospacers and PAM sites in the four genomic locations to be targeted. b The targeting efficiency by the low copy number vector pTRKL2 based CRISPR/Cas9 system. When transforming NZ9000 with pTLCas9galk1 (or pTLCas9hemN1, pTLCas9recA1, pTLCas9noxD1), there was a 105-fold reduction in viable colonies compared to transformation with pTLCas9 (control). c Reduction of the off-target effects in L. lactis. The Cas9, tracrRNA and crRNA were carried by the high copy number plasmid pTRKH2. The spacer sequence was set as 20 bp, 25 bp and 30 bp for each of the four genomic locations. Statistically significant differences are indicated by asterisks (*P < 0.05; **P < 0.01). The values are means ± standard deviations of three independent experiments