Fig. 2: Super-adaptation phenotype is caused by Δtracr or lack of crRNA.
From: Cas9 senses CRISPR RNA abundance to regulate CRISPR spacer acquisition
a, Schematic of CRISPR–Cas9 loci of WT and Δtracr N. meningitidis strains. b, Δtracr and its derivatives complemented with tracrRNA or empty vector, and a ΔtracrΔcas9 strain was assayed for MDAΦ infection and acquisition, with or without induction of cas1–2. Top, a representative adaptation PCR gel. Bottom, quantification of adaptation efficiencies. Data are mean ± s.d., n = 3. NS (P ≥ 0.05), *0.005 ≤ P < 0.05 and **P < 0.005; P values calculated by two-tailed Welch’s t-tests. c, 3′ Flanking motif analysis for new viral spacers from b. Lx, lane number. d, Schematic of CRISPR–Cas9 loci of WT and crRNA null allele R26. e, R26 and its derivative strain lacking cas9 were assayed for MDAΦ infection and acquisition, with or without the IPTG induction of cas1–2. Top, a representative adaptation PCR gel. Bottom, quantification of adaptation efficiencies. Data are mean ± s.d., n = 3. NS (P ≥ 0.05), *0.005 ≤ P < 0.05 and **P < 0.005; P values calculated by two-tailed Welch’s t-tests. CR, CRISPR; FL, full length. f, 3′ Flanking motif analysis for new viral spacers from e. nt, nucleotide.
