Allele-specific transcription factor occupancy at the MEG3 enhancer. A: Schematic representation of the allele-specific ChIP experimental design. Transcription factor ChIP is performed on islets from donors heterozygous for the SNP rs3783355. Following amplification using primers surrounding the SNP, the PCR products are sequenced to quantitatively determine the relative representation of the two alleles. B: Relative amplification (percent sequencing reads) of the rs3783355 alleles as determined by high-throughput sequencing of input, NKX2.2, FOXA2, and PDX1 ChIP DNA from islet donors heterozygous for rs3783355 (G/A). C: The minor allele of rs3783355 alters the recognition sequence of a restriction enzyme, BanII. Following ChIP-PCR to determine FOXA2 occupancy at the MEG3 enhancer, the PCR products were digested with BanII to qualitatively assess the allelic representation of rs3783355. A representative gel of BanII-digested input and FOXA2 ChIP-PCR products from islets from two donors heterozygous for rs3783355 is shown. Data are represented as mean ± SEM. P values calculated using Student t test. ***P < 0.001.