Figure 2

The 5,6-dichloro-1-beta-D-ribofuranosylbenzimidizole (DRB)- stimulated introduction of H3K9me2 and H3K9me3 is partially dependent upon ongoing DNA Replication. Wild-type SV40 minichromosomes were isolated at 48 hr post-infection with or without treatment with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidizole (DRB) and aphidicolin from 24 to 48 hr post-infection. The treated and untreated intact minichromosomes were subjected to ChIP analyses with antibodies to H3K9me2 and H3K9me3 and the percentages of the minichromosomes containing the modified H3K9s determined by real-time PCR amplification of the bound intact SV40 genomic DNA with primers recognizing the promoter region. The fold increase in the percentages of minichromosomes containing H3K9me2 and H3K9me3 was then calculated.