Figure 4.

KAP1 Recruitment and H3K9 Trimethylation at Imprinting Control Regions Require DNA Methylation

(A) HA-specific ChIP in control (WT) and Dnmt1/3a/3b-deleted (DNMTs TKO) ES cells expressing a HA-tagged form of KAP1 and transduced with an MLV-based retroviral vector, with primers for indicated genomic and virus-derived (MLV PBS) sequences. Error bars indicate standard deviation, and the difference between control and TKO cells is always significant (p < 0.01, n = 3), except for the GAPDH and MLV PBS.

(B) Same analysis with H3K9me3-specific antibody-mediated ChIP. Histone 3 trimethylation of ICRs, but not of IAP chromatin, is abolished in the absence of DNA methylation. Error bars indicate standard deviation, and the difference between control and TKO cells is always significant (p < 0.01, n = 3), except for the GAPDH and IAP LTR. KV, KvDMR1 ICR.