Figure 5

Cis -eQTL are enriched for active but not repressive histone marks in colonic mucosa. The red histogram in each plot depicts the distribution of the number of SNPs in histone mark peaks in 1,000 randomly selected cis-eQTL SNP sets, which are generated by randomly selecting a single SNP for each unique cis-eQTL target gene (n = 684) among all cis-eQTL (FDR < 0.10) that are significantly associated with the expression of that gene. The blue histograms represent the distributions of the number of SNPs in histone mark peaks in 1,000 randomly sampled SNP sets, each matching the set of 684 significant cis-eQTL SNPs (chosen at random from the set of 1,000 cis-eQTL SNPs depicted in red) with respect to MAF and distance from the nearest TSS. Four markers of active chromatin (H3K4me1, H3K4me3, H3K9ac and H3K36me3) are depicted in (A), while a single marker of inactive chromatin (H3K9me3) is depicted in (B). The p-value in the top right corner of each histogram is the empirical p-value obtained by comparing the number of SNPs in histone mark peaks in the 1,000 sets of cis-eQTL SNPs (red) to the null distribution given by the 1,000 sets of matched SNPs (blue).