Practice question

Pluripotency of inner cell mass and derived embryonic stem cells depends on core transcription factor circuit Oct4 Sox2 Nanog forming feed-forward autoregulatory loop. These factors co-bind promoters of self-renewal genes while repressing differentiation drivers like Cdx2 and Gata6 via chromatin remodeling. Active Hippo pathway retaining YAP cytoplasmically permits sustained expression. Withdrawal of any component collapses pluripotency causing precocious trophectoderm or primitive endoderm differentiation. Triad therefore maintains naive state ensuring capability to generate all embryonic lineages upon gastrulation signals, implantation cues, developmental progression and differentiation stimuli in embryogenesis.