Molecular coupling of Tsix regulation and pluripotency

Reprogramming of X-chromosome inactivation during the acquisition of pluripotency is accompanied by repression of Xist, the trigger of X-inactivation, and by upregulation of its antisense counterpart, Tsix. In undifferentiated embryonic stem cells (ESCs), key transcription factors that support pluripotency repress Xist transcription. These authors show that upregulation of Tsix in ESCs depends on a different subset of pluripotency factors. Therefore, two distinct ESC-specific complexes couple reprogramming of X-inactivation to pluripotency.