Incomplete DNA methylation underlies a transcriptional memory of somatic cells in human iPS cells

A systematic comparison shows that differential DNA methylation accounts for some of the differences in somatic gene expression between induced pluripotent stem cells (iPSCs) and embryonic stem cells. The somatic genes that have persistent expression in iPSCs tend to be isolated from other genes that undergo silencing during reprogramming. This may explain the observed delay in recruitment of the DNA methylation machinery and in the genes being silenced.