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#determined cell

2 public questions tagged with this topic.

Which of the following is NOT a feature of a determined cell?

Determined cells exhibit stable, self-sustaining commitment enforced by profound molecular mechanisms including DNA methylation, Polycomb-mediated repression of alternative lineage genes, histone modifications and positive autoregulatory transcription factor loops that maintain expression without ongoing external signals. This epigenetic lockdown allows autonomous differentiation even when placed in ectopic environments exposing them to contradictory cues that would normally redirect naive cells. Concept of reversible fate contradicts determination definition; labile reversal applies to specified but undetermined stages rather than determined. Thus determined state resists experimental reprogramming without nuclear transfer or induced pluripotency manipulation.

Ref: Gilbert, Developmental Biology, 12th ed., Chapter 5: Properties of Determined Cells and Stability.

What happens if a specified but not determined cell is transplanted into another region of an embryo?

A cell that is specified but not yet determined retains considerable responsiveness to environmental cues. When heterotopically transplanted into a different embryonic region, surrounding inductive signals such as BMP antagonists, Wnt ligands, FGFs or Notch ligands can overwrite initial bias and respecify fate to match host location, reflecting open chromatin and continued receptor expression. This plasticity distinguishes specification as labile phase. Once determination occurs, epigenetic barriers including DNA methylation and Polycomb-mediated repression, plus autoregulatory transcription loops, prevent redirection, causing cells to differentiate according to origin regardless of new surroundings, revealing transition to stabilized commitment.

Ref: Gilbert, Developmental Biology, 12th ed., Chapter 5: Lability of Specified Cells Upon Transplantation.