Practice question

Determination is conceptualized as the stable, essentially irreversible commitment of a cell to a particular differentiation pathway, following an earlier labile specification phase. During specification, fate preference is established but can still be redirected by changing embryonic environment or transplantation. Determination involves profound molecular stabilization including positive feedback loops among selector genes like MyoD in myoblasts, extensive chromatin remodeling, DNA methylation and Polycomb-mediated repression of alternative programs. Once determined, cells execute differentiation autonomously even when grafted into foreign regions that would normally induce different fates, maintaining original identity despite contradictory signals.