The Epigenetic Landscape of Latent Kaposi Sarcoma-Associated Herpesvirus Genomes
Figure 8
Bivalent histone modification patterns at the ORF50 promoter are reversed upon induction of the lytic cycle.
A: Profiles of H3K9/K14-ac (blue), H3K4-me3 (red) and H3K27-me3 (black) histone modifications at the ORF21 (left), ORF50 (center) and ORF73 (right) loci of BCBL1 cells. Black bars indicate the location of regions amplified by quantitative PCR in the sequential ChIP and lytic reactivation experiments shown in B–D. B, C: Sequential ChIP experiments carried out with antibodies directed against H3K9/K14-ac and H3K27-me3 during the first and second rounds of immunoprecipitation, respectively (B), or with antibodies against H3K27-me3 during the first ChIP, followed by H3K4-me3 specific antibodies for the second immunoprecipitation (C). For the first as well as the second round of immunoprecipitation, numbers on the y-axis indicate the percentage of recovered material relative to the total starting material (i.e., the amount of DNA which was used as the input during the first ChIP). D: Reversal of H3K27-me3 marks at the ORF50 promoter upon lytic reactivation. BCBL1 cells were treated with 0.3mM sodium butyrate to induce the lytic cycle. ChIP experiments were performed at the indicated time points to monitor changes in H3K27-me3 and H3K9/K14-ac modification patterns, using quantitative PCR with primers specific for the p50 −800 region as shown in A.