FIG 6 .

Model of histone modification changes during highly virulent respiratory virus infection. Viral infection induces changes in the basal state of host chromatin. For H1N1-09 and SARS-CoV, infection results in H3K4me3 incorporation (green ovals), reduced H3K27 (red diamonds), and an open confirmation. In contrast, for H5N1-VN1203 and MERS-CoV, infection augments H3K27me3 incorporation and reduces H3K4me3 for a subset of genes, resulting in a closed conformation that excludes activated transcription factors and represses ISG expression.