Fig. 2

Mining of NPC-associated DMRs in the EBV genome. a BamHI restriction map of the EBV genome is shown. b Methylation densities of CpG loci across the EBV DNA genome from the pooled sequencing data of the 15 cases of NPC and the pooled data of the 5 cases of infectious mononucleosis used for mining of DMRs. Each dot (grey and coloured) shows the methylation density at a corresponding CpG site. A DMR was constructed by two or more differentially methylated CpG sites (>80% in the pooled data of NPC and <60% in the pooled data of infectious mononucleosis) within 200 bp. The coloured dots highlight those CpG sites which fulfilled our criteria. The red dots are those CpG sites with the methylation densities greater than 80% in the pooled data of NPC and the blues dots are those with the methylation densities less than 60% in the pooled data of infectious mononucleosis. Viral DNA fragments mapped to the BamHI-W repeat region presented ambiguities in alignment to the exact member of the repeat family. Hence, this region was not used in the final approach