Figure 2. Histone H3 K4 methylation states at the genomic loci of key adipogenic regulators during 3T3-L1 adipogenesis. Levels of histone H3 K4 (A) mono-methylation, (B) di-methylation and (C) tri-methylation at the genomic loci of the key adipogenic regulators Pref-1, C/EBPβ, C/EBPα, PPARγ2 and aP2 during the adipogenesis of 3T3-L1 cells were examined by ChIP analysis using specific antibodies. The ChIP-qPCR primers used in this study were as follows: Chr. 15, which targets a silent region on mouse chromosome 15 containing no known gene within 500 kb; GAPDH, which targets the promoter region of the actively transcribed GAPDH gene and -2 kb and -1 kb primers, which target regions 2 kb and 1 kb upstream of the TSS, respectively. Promoter primers target regions within 500 bp upstream of the TSS. UTR primers were designed to target large conserved 3′-UTRs in the C/EBPα and C/EBPβ gene sequences. Details of these primers are given in the Experimental Procedures section. ChIP samples were collected at the indicated time points during adipogenesis. These results are the averages of three independent ChIP-qPCR assays, and the error bars indicate standard deviations.