Mirco Galiè summarizes studies supporting the hypothesis that the partially or fully mesenchymal phenotype represents a general paradigm of stem cell plasticity underlying embryonic development, regenerative potential, and their pathological counterparts:
doi.org/10.1016/j.diff.2025.…
ALT Fig. 2. According to the traditional concept of mesenchyme, during embryonic development, mesenchymal-like tissues form through EMT from epithelial-shaped tissues in two major steps at the early stages of gastrulation. Specifically, the primary mesenchyme originates from the epiblast to form mesoderm and primitive endoderm; this process is regarded as the prototype of EMT. Subsequently, the mesoderm reverts to an epithelial morphology to generate transient embryonic structures, including somites, which then undergo a further round of EMT to generate secondary mesenchyme. Secondary mesenchyme is considered the embryonic connective tissue and provides the precursors of the connective tissues of the adult body.