| Abstrakt: |
These results provide new experimental evidence toward a further understanding of the rôle which the blastema plays in regeneration. It has been previously established (Schotté and Butler,7, 8Butler and Schotté9) that in normal regeneration cessation of dedifferentiation of formed structures of the limb coincides with the appearance of a blastema. It has been demonstrated, furthermore, that when the formation of a blastema is prevented by denervation, dedifferentiation is unchecked and proceeds to extreme ends. In the experiments here reported it is shown that this extreme dedifferentiation in an amputated nerveless limb is prevented by the transplantation of a young blastema.The presence of a blastema, therefore, is essential for the cessation of dedifferentiation and hence for the establishment of an equilibrium in the cellular interactions which occur during the initial phases of regeneration. This is true, however, only for young undifferentiated blastemas. When a transplanted blastema itself shows unmistakable signs of differentiation, it loses the capacity to control the dedifferentiation of a nerveless amputated limb. |
