TET activity propagates transcriptional memory through embryonic dormancy

ABSTRACT: Dormancy is an essential biological process for the propagation of many life forms through generations and stressful conditions. Early embryos of many mammals are preservable for weeks to months within the uterus under dormancy, which can be induced in vitro through mTOR inhibition. Dormancy features silencing of the genome and abundant heterochromatin formation, which conflicts with the permissive and uncommitted genomic profile of pluripotent cells. Cellular strategies to maintain pluripotency in the fate of this conflict are not known. Here we probed chromatin regulation during embryonic stem cells’ (ESC) entry into dormancy to identify mechanisms that ensure faithful propagation of cellular identity through dormancy. We show a global increase in DNA methylation and loss of chromatin accessibility in dormant ESCs and find that TET DNA demethylases are essential to counteract this trend at key pluripotency regulatory elements, particularly at young LINE1 repeats and active enhancers. Demethylation of these targets by TETs is essential for transcription factor (TF) recruitment and transient chromatin decondensation before hypercompaction. We propose that key regulatory elements are bookmarked coordinately by TETs and TFs in dormancy for maintenance of cellular identity. Perturbation of TET activity compromises embryo survival through dormancy; whereas its enhancement improves survival rates. Our results reveal the first essential chromatin regulator in establishing mammalian embryonic dormancy and pave the way to building its temporal regulatory code in embryonic and adult tissues.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Embryonic Stem Cell

SUBMITTER: David Meierhofer  

LAB HEAD: Aydan Bulut-Karslioglu

PROVIDER: PXD039056 | Pride | 2024-03-22

REPOSITORIES: Pride