Data from: Dissecting gene activation and chromatin remodeling dynamics in single human cells undergoing reprogramming

During cell fate transitions, cells remodel their transcriptome,
chromatin, and epigenome; however, it has been difficult to
determine the temporal dynamics and cause-effect relationship between
these changes at the single-cell level. Here, we employ the
heterokaryon-mediated reprogramming system as a single-cell model
to dissect key temporal events during early stages of
pluripotency conversion using super-resolution imaging. We reveal
that, following heterokaryon formation, the somatic nucleus undergoes
global chromatin decompaction and removal of repressive histone
modifications H3K9me3 and H3K27me3 without acquisition of
active modifications H3K4me3 and H3K9ac. The pluripotency gene
OCT4 (POU5F1) shows nascent and mature RNA transcription within
the first 24 h after cell fusion without requiring an initial open
chromatin configuration at its locus. NANOG, conversely, has
significant nascent RNA transcription only at 48 h after cell fusion
but, strikingly, exhibits genomic reopening early on. These
findings suggest that the temporal relationship between chromatin
compaction and gene activation during cellular reprogramming is gene
context dependent.