News Finding: They then found that the loss of SMCHD1 prevented the spreading of Xist across the chromosome and kept the two large domains, which the team named S1 and S2 compartments, from being merged into the typical compartment-less inactive X structure.
Paper Finding: With its ATPase domain Chen et al., 2016) , SMCHD1 might serve as Xist's engine to drive attenuation of both compartments and TADs to complete the final Xi transformation.
News Context: The team's experiments in mouse cells first confirmed that the presence of SMCHD1 was necessary for the silencing of a large subset of genes on the inactive X chromosome. They then found that the loss of SMCHD1 prevented the spreading of Xist across the chromosome and kept the two large domains, which the team named S1 and S2 compartments, from being merged into the typical compartment-less inactive X structure. By bridging the S1 and S2 compartments, SMCHD1 was found to induce their merging into the conformation that prevents gene expression.
Paper Context: This idea is supported by the nearly homogeneous distribution of SMCHD1 on the Xi, contacting both S1 and S2 compartments ( Figure 6 ). With its ATPase domain Chen et al., 2016) , SMCHD1 might serve as Xist's engine to drive attenuation of both compartments and TADs to complete the final Xi transformation. Future work will test our stepwise folding Origami Model.