Fig. 4

Relative expression of Module 1 components in S. aureus reference strains. RNA-Seq analysis of NCTC 8325, S0835, MRSA252 and HO 5096 0412, representatives of essC1, essC2, essC3 and essC4 variants respectively, was carried out to measure and compare the transcription of the Module 1 genes: esxA, esaA, essA, esaB, and essB. For each strain the mean fragments per kilobase of transcript per million mapped reads (FPKM) were calculated and normalized, using the expression value of the housekeeping gene rpoD. The normalized logFPKM values for each of the components of the Module 1 are plotted along with the values for essC, the first gene of Module 2 which is transcriptional linked to Modules 1 genes, esaA, essA, esaB, and essB