Figure 1.

ATAC-seq results in sorted human α-, β-, and acinar cells. (A) Experimental design. Islets from deceased organ donors were dispersed and FACS sorted into α-, β-, and acinar cell fractions, and processed for ATAC-seq analysis. N: nucleosome; T: transposase. Red and green bars represent PCR/sequencing barcodes. (B) Fragment lengths within a representative ATAC-seq library. The small fragments represent sequence reads in open chromatin, while the peak at ∼150 bp results from sequence reads that span one nucleosome, and larger peaks represent progressively more compact chromatin. (C) Heatmap of ATAC-seq peak data showing clustering of endocrine-selective peaks (present in α- and β-, but not acinar cells), α-cell-selective peaks, and β-cell-selective peaks. Inter-sample correlation is noted at the bottom. (D) Number of peaks identified by ATAC-seq in each cell type that are specific to that cell type versus also found in either of the other two cell types investigated. (E) Venn diagram of overlap of α-cell-selective and β-cell-selective ATAC-seq peaks, after removal of peaks also found in acinar cells.