Scholpp_LabWhat is cellular competence? According to Spemann and Waddington, competence is the ability to respond to an inducing signal. Waddington visualized this concept through his famous epigenetic landscape model, where development is guided along stable paths (canals) despite potential perturbations.
Therefore, competence is foremost defined by the availability of the appropriate receptor to be able to respond to a particular signal (ability to react).
Sally Lowell@scholpp_lab_LSI Do you mean competence to change identity in response to a signal? I'd say this is defined by many different chemical and physical properties of the cell - including receptor availability, as you say. But, in most (although certainly not all) cases I'd say it is *foremost* defined in the nucleus (state of chromatin + GRN). Even so, nevertheless, and notwithstanding - receptors are important! So your main argument still stands 🙂 #DevBio
@CellySally I agree with everything you said. However, could a cell react without the external trigger of a chemical signal? And how could this cell react if it would not express the appropriate receptor for signal integration? Everything else will follow. #morphogen #morphogenesis #DevBio
Ian SudberyCells can respond to mechanical as well as chemical signals.
Although perhaps that is pedantry, as something must also be sensing the mechanical changes. Why not call it a receptor?
@CellySally @IanSudbery Excellent point, Ian. However, I am unaware of evidence that mechanical signals can assign a specific "competence" to a cell, e.g., to acquire a particular cellular fate—similar to morphogens. Please correct me if I am wrong. I am a big fan of the idea that cells integrate mechanical and chemical stimuli to achieve a specific outcome. The only evidence I could find is a recent publication from the Mayor lab: https://www.nature.com/articles/s41556-024-01378-y.
Yeah, I don't have any concrete examples: I'm not particularly an expert in this - something I am just learning about at the moment through some new collaborations.
Jocelyn Etienne@IanSudbery @scholpp_lab_LSI @CellySally
20 years after, what is the state of the debate on the stiffness-related initiation of differentiation?
Steffen 🐟@jocelyn_etienne @IanSudbery @scholpp_lab_LSI @CellySally Yes, stiffness of the ECM is essential. However, the authors also say that the different environments still require the “addition of soluble induction factors”. That leads us back to the ligand-receptor discussion, I guess.