Fig. 3: Effect of phage capsid remodelling on plasmid transfer.
From: Staphylococcal phages and pathogenicity islands drive plasmid evolution
RN4220 strains lysogenic for phage 80α (WT or carrying the capsid remodelling cpmAB genes from SaPI1) with SaPI1 (WT or mutant in cpmAB) carrying plasmids a pC221 (4.6 kb; blue circles) or b pI258 (29 kb; green circles) were induced with mitomycin C to produce lysates. Log10 transductants (TrU) per ml were determined for each plasmid in an RN4220 recipient. SaPI1 mutants in cpmAB are incapable of small SaPI-sized capsid production so only produce phage-sized capsids (~45 kb capacity); the 80α::SaPI1cpmAB mutant overwhelmingly redirects capsid production to small SaPI-sized particles (~15 kb capacity) incapable of accommodating phage DNA. All data is the result of three independent experiments (n = 3). Data for each donor strain are represented as boxplots where the middle line (bold) is the median, the lower and upper hinges correspond to the 25th and 75th percentiles, and the whiskers extend from the minimum to maximum values, with all individual data points shown as coloured circles. A one-way ANOVA with Tukey’s multiple comparisons tests compared mean differences between each group and the 80α control. Asterisks denote significant adjusted p values: a ****p < 0.0001; b * 80α vs 80α SaPI1 p = 0.0270, ****p < 0.0001, * 80α vs 80α::SaPI1cpmAB SaPI1 p = 0.0125. All other values were not statistically significant.
