Blastema in epimorphosis primarily consists of:
Epimorphic blastema formed after amputation does not consist of pluripotent embryonic stem cells but of lineage-restricted yet multipotent progenitor cells derived via dedifferentiation of stump tissues. Muscle-derived blastema cells predominantly regenerate muscle, dermal fibroblasts generate cartilage and connective tissue, Schwann cells generate nerves, yet plasticity permits limited transdifferentiation under signals. Single-cell transcriptomics show blastema cells express progenitor markers Prrx1, Msx1, maintain positional memory via Meis, Hox gradients. Thus blastema comprises multipotent progenitor pool capable of producing multiple cell types needed for limb reconstruction while retaining memory of tissue origin and position.
Ref: Gilbert, Developmental Biology, 12th ed., Chapter 21: Blastema composition as multipotent progenitors in epimorphosis.