Islet cells share promoter hypomethylation independently of expression, but exhibit cell-type-specific methylation in enhancers.

ABSTRACT: DNA methylation at promoters is an important determinant of gene expression. Earlier studies suggested that the insulin gene promoter is uniquely unmethylated in insulin-expressing pancreatic β-cells, providing a classic example of this paradigm. Here we show that islet cells expressing insulin, glucagon, or somatostatin share a lack of methylation at the promoters of the insulin and glucagon genes. This is achieved by rapid demethylation of the insulin and glucagon gene promoters during differentiation of Neurogenin3⁺ embryonic endocrine progenitors, regardless of the specific endocrine cell-type chosen. Similar methylation dynamics were observed in transgenic mice containing a human insulin promoter fragment, pointing to the responsible cis element. Whole-methylome comparison

SUBMITTER: Neiman D 

PROVIDER: S-EPMC5754795 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature