@article{f0035ddcbde3429b8b5d56fb45e24f8b,
title = "Disabling de novo DNA methylation in embryonic stem cells allows an illegitimate fate trajectory",
abstract = "Genome remethylation is essential for mammalian development but specific reasons are unclear. Here we examined embryonic stem (ES) cell fate in the absence of de novo DNA methyltransferases. We observed that ES cells deficient for both Dnmt3a and Dnmt3b are rapidly eliminated from chimeras. On further investigation we found that in vivo and in vitro the formative pluripotency transition is derailed toward production of trophoblast. This aberrant trajectory is associated with failure to suppress activation of Ascl2. Ascl2 encodes a bHLH transcription factor expressed in the placenta. Misexpression of Ascl2 in ES cells provokes transdifferentiation to trophoblast-like cells. Conversely, Ascl2 deletion rescues formative transition of Dnmt3a/b mutants and improves contribution to chimeric epiblast. Thus, de novo DNA methylation safeguards against ectopic activation of Ascl2. However, Dnmt3a/b-deficient cells remain defective in ongoing embryogenesis. We surmise that multiple developmental transitions may be secured by DNA methylation silencing potentially disruptive genes.",
keywords = "DNA methylation, Embryonic stem cells, Pluripotency",
author = "Masaki Kinoshita and Li, {Meng Amy} and Michael Barber and William Mansfield and Sabine Dietmann and Austin Smith",
note = "Funding Information: We thank Brian Hendrich and Jennifer Nichols for comments on the manuscript and Giuliano Stirparo for advice on informatics. We are grateful to Tim Lohoff and Jennifer Nichols for discussion of unpublished data. We thank Maike Paramor, Vicki Murray, Peter Humphreys, Darran Clements, Andrew Riddell, and biofacility staff for technical support and the Cambridge Stem Cell Institute (CSCI) core bioinformatics team for data processing. Sequencing was performed by the Cancer Research UK Cambridge Institute Genomics Core Facility. Rosalind Drummond and James Clarke provided laboratory assistance. This research was funded by the Biotechnology and Biological Sciences Research Council (BB/P009867/1, BB/P021573/1) and the Medical Research Council (MR/P00072X/1). The CSCI receives core funding from Wellcome (203151/Z/16/Z) and the Medical Research Council (MC_PC_12009). A.S. is a Medical Research Council professor (G1100526/1). Funding Information: ACKNOWLEDGMENTS. We thank Brian Hendrich and Jennifer Nichols for comments on the manuscript and Giuliano Stirparo for advice on informatics. We are grateful to Tim Lohoff and Jennifer Nichols for discussion of unpublished data. We thank Maike Paramor, Vicki Murray, Peter Hum-phreys, Darran Clements, Andrew Riddell, and biofacility staff for technical support and the Cambridge Stem Cell Institute (CSCI) core bioinformatics team for data processing. Sequencing was performed by the Cancer Research UK Cambridge Institute Genomics Core Facility. Rosalind Drum-mond and James Clarke provided laboratory assistance. This research was funded by the Biotechnology and Biological Sciences Research Council (BB/ P009867/1, BB/P021573/1) and the Medical Research Council (MR/P00072X/1). The CSCI receives core funding from Wellcome (203151/Z/16/Z) and the Medical Research Council (MC_PC_12009). A.S. is a Medical Research Council professor (G1100526/1). Publisher Copyright: {\textcopyright} 2021 National Academy of Sciences. All rights reserved.",
year = "2021",
month = sep,
day = "21",
doi = "10.1073/pnas.2109475118",
language = "English",
volume = "118",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "38",
}