Asymmetric dimethyl H4R3 correlates with transcriptional activation of the β-globin gene. (A) Schematic representation of the 135-kbp mouse β-globin locus. The globin genes are indicated by red boxes, and DNase I hypersensitive sites (HS) are indicated by arrows. The locations and names of primers used for the ChIP-quantitative PCR (qPCR) assay are indicated below the locus. (B) Fetal livers were prepared from E14.5 mouse embryos and isolated as single-cell suspensions. The cells were cross-linked with formaldehyde and sonicated for ChIP-qPCR analysis using α-dimethyl H4R3 antibody or normal rabbit immunoglobulin G (IgG) as a control. The relative enrichment of dimethyl H4R3 for each amplicon was determined by 3 independent experiments. (C) ChIP analysis of dimethyl H4R3 at the endogenous mouse β-globin locus in E14.5 fetal brain. (D-E) Yolk sacs were prepared from wild-type or dominant-negative USF1-expressing transgenic embryos at E10.5 and subjected to ChIP-qPCR across the globin locus using PRMT1- (D) or dimethyl H4R3–specific (E) antibodies. Significant difference by Student t test: **P < .01.