Morphallaxis

Morphallaxis is a biological process in which an organism regenerates a part of its body by reorganizing its existing cells, rather than by cell proliferation. This process is distinct from epimorphosis, where regeneration occurs through the growth of new cells. Morphallaxis is observed in various species, particularly in simpler organisms such as hydra and some annelids.

Mechanism

Morphallaxis involves the reorganization of pre-existing tissues to replace lost or damaged parts. This process typically does not involve significant cell division. Instead, cells at the site of injury undergo dedifferentiation, migrate to the wound site, and then redifferentiate to form the new structure. This allows the organism to restore its form and function efficiently.

Examples

One of the most well-known examples of morphallaxis is seen in the hydra, a small freshwater organism. When a hydra is cut into two pieces, each piece can reorganize its cells to form a complete, smaller hydra. This remarkable ability is due to the high plasticity of the hydra's cells and their capacity to change their roles as needed.

Another example is found in certain species of annelids, such as the earthworm. When an earthworm is cut, the posterior part can regenerate a new head through morphallaxis, although this ability varies among different species.

Comparison with Epimorphosis

While morphallaxis relies on the reorganization of existing cells, epimorphosis involves the proliferation of new cells to replace lost tissues. Epimorphosis is more common in more complex organisms, such as salamanders and newts, which can regenerate limbs through the formation of a blastema, a mass of undifferentiated cells that proliferate and differentiate to form the new structure.

Significance

Understanding morphallaxis provides insights into the fundamental mechanisms of regeneration and cellular plasticity. It also has potential implications for regenerative medicine, where harnessing similar processes could lead to advances in healing and tissue repair in humans.

Related Pages

• Regeneration
• Epimorphosis
• Hydra (genus)
• Annelid
• Cellular differentiation
• Regenerative medicine