Collapse of active nuclear compartment by Xist RNA binding HnrnpU, evicting RNAPII.
Genome ReOrganization Upon Pluripotency-exit (GRO-UP) acts on Xa/Xi, parallel to XCI.
GRO-UP silences gene-poor, LINE1-rich DNA while Xist localizes to gene-rich islands.
Xist recruits Spen for initial gene silencing, locked in by PRC1/2 and/or macroH2A.
Smchd1 compacts the hypoacetylated Xi across mutually reinforcing H3K9me2/3 & H3K27me3 domains.