Figure 4. Mononucleotide SSRs in the 60 mutated genes compared with the genome coding region of P. aeruginosa PACS2.

The plots show the numbers of mononucleotide G:C SSRs (A) and A:T SSRs (B) (normalized to SSR count every 10⁵ bp) in the pooled coding sequence of the 60 genes mutated during the process of chronic infection (red curve) and in the 99% prediction region (grey area) estimated by re-sampling 60 genes at random, with reposition, from the whole coding genome of P. aeruginosa PACS2. The sampling was repeated 50000 times to obtain a good estimation of empirical distributions of SSR counts. From these distributions the extreme 0.5% and 99.5% quantiles were estimated to build the 99% prediction intervals for each length of SSR. Points of the curve which fall outside of the prediction area were considered to be statistically significant (p = 0.01).