I am trying to model bone remodeling process and I wonder what is the difference between phenotype switching and differentiation. I am relatively inexperienced in biology. Please explain me with examples related to this context. Thanks in advance.
Differentiation is a process which occurs in multiple steps. A precursor cell for example a mesenchymal stem cell can proliferate (divide/multiple). The stem cell can commit to become a progenitor cell (osteoprogenitor cell) which can still proliferate but has acquired the possibility to differentiate to a different cell type. In some cases or when specific conditions are met,the progenitor can differentiate to a pre-osteoblast and finally to a mature osteoblast.
The differentiation process require the activation of a specific transcription program and leads to large changes in the cell like morphology, size, and function. Once differentiated, the cell cannot proliferate anymore and loss the capacity to divide.
Phenotype switching can be broadly defined as any change in the phenotype like morphological change, expression of specific biomarkers, etc. In the context of differentiation phenotype switching refers to the acquisition of a specific differentiation marker usually a transcription marker like Runx2. While they might not be a large morphological change, the fact that the cell express this transcription factor indicates it is switching phenotypes and starting differentiation.
In summary: differentiation is process which occurs in multiple distinct steps. Differentiated states are characterized by a specific morphology, acquisition of key bio markers (usually transcription factors), loss of the capacity to proliferate, and a cellular specific function. Phenotype switching refers to the time frame when a cell changes from one phenotype to another; when it acquires or loss a defined morphological state or key markers.