The Lability of the Differentiated State
Many classical studies have shown that cell fates become progressively restricted during development and that this restriction is typically irreversible. This has led to the dogma of the Stability of the Differentiated State: cells cannot typically move from one differentiated state to another.
The recent reports of experimental manipulation of cell differentiation and fate by use of transcription factors must lead to a reevaluation of this concept. Retrospectively these results should not surprise us as there are many well-established examples of „trans-differentiation“, both in spontaneous regeneration and in particular experimental situations.
Differentiation is a metastable state and as we start to understand mechanism simple dogmas prove unhelpful guides.