Editing Cellular differentiation (section)

=====In stem cells=====
{{further|Stem cell}}

During differentiation, stem cells change their gene expression profiles. Recent studies have implicated a role for nucleosome positioning and histone modifications during this process.<ref name = "Teif_et_al">{{cite journal | vauthors = Teif VB, Vainshtein Y, Caudron-Herger M, Mallm JP, Marth C, Höfer T, Rippe K | title = Genome-wide nucleosome positioning during embryonic stem cell development | journal = Nature Structural & Molecular Biology | volume = 19 | issue = 11 | pages = 1185–1192 | date = November 2012 | pmid = 23085715 | doi = 10.1038/nsmb.2419 | s2cid = 34509771 }}</ref> There are two components of this process: turning off the expression of embryonic stem cell (ESC) genes, and the activation of cell fate genes. Lysine specific demethylase 1 ([[LSD1|KDM1A]]) is thought to prevent the use of [[enhancer (genetics)|enhancer]] regions of pluripotency genes, thereby inhibiting their transcription.<ref name="ReferenceB">{{cite journal | vauthors = Whyte WA, Bilodeau S, Orlando DA, Hoke HA, Frampton GM, Foster CT, Cowley SM, Young RA | title = Enhancer decommissioning by LSD1 during embryonic stem cell differentiation | journal = Nature | volume = 482 | issue = 7384 | pages = 221–225 | date = February 2012 | pmid = 22297846 | pmc = 4144424 | doi = 10.1038/nature10805 | bibcode = 2012Natur.482..221W }}</ref> It interacts with [[NuRD|Mi-2/NuRD complex]] (nucleosome remodelling and histone deacetylase) complex,<ref name="ReferenceB"/> giving an instance where methylation and acetylation are not discrete and mutually exclusive, but intertwined processes.