What are Dedifferentiation and Redifferentiation?
What are Dedifferentiation and Redifferentiation?
Dedifferentiation
A single multicellular organism is made up of a diverse range of cell types. Through a series of division and differentiation steps, all of these cells are generated from a zygote. A specific cell type splits early in an organism’s development, and its offspring gradually establish persistent variations in appearance, structure, and function, eventually creating a variety of cell phenotypes. Differentiation is the essential foundation for progress. Cells become increasingly confined to a single cell type during animal development, and their ability to react to a range of differentiation cues decreases with each generation. To put it another way, the process of differentiation steadily decreases a cell’s potential. The cell is considered to stop dividing permanently after the end of differentiation.
There is now a lot of evidence that certain differentiated cells have the extraordinary capacity to change into an entirely other phenotype. Transdifferentiation is the process of switching from one cellular phenotype to another. Transdifferentiation is most often associated with amphibian limb regeneration and the conversion of pigment epithelia into lens and neural retinal cells. In reality, the trans-differentiation process is divided into two stages. The differentiated cells revert to cells with a stem cell or progenitor cell characteristic in the first phase. These dedifferentiated cells redifferentiate into new, differentiated cell phenotypes in the second phase. Conversion of pancreatic cells to hepatocytes and vascular endothelium to smooth muscle are two more examples of transdifferentiation. Rather than direct transdifferentiation, all of these experimental data lead to a dedifferentiation–redifferentiation paradigm.
Dedifferentiation is the process by which cells go from a highly differentiated to a less differentiated state in reverse order. At the gene, protein, morphology, and function levels, the phenomena can be observed. The cell switches from a differentiated cell gene expression profile to a progenitor cell gene expression profile on a genetic level. Development-related gene activity is suppressed during dedifferentiation, whereas genes that preserve the cell undifferentiated are active. The up-regulation of progenitor cell–related proteins and the down-regulation of differentiated cell–related proteins are indications of dedifferentiation at the protein level. Cells undergo morphological changes during dedifferentiation: dedifferentiated cells are smaller, have fewer organelles, and have a greater karyoplasmic ratio than mature cells. Finally, the cell’s functional capacity to multiply is restored, allowing a postmitotic cell to resume the cell cycle. Meanwhile, mature or lineage-committed cells may develop into multipotent or pluripotent progenitor cells capable of differentiating into a wide range of cell types.
During dedifferentiation, changes occur at all four levels. Despite the fact that many studies claim to have seen dedifferentiation, their conclusions were based on only one or two of the symptoms described above. There has yet to be established a definitive, widely recognised criterion for dedifferentiation. Researchers are discovering components that may turn out to be similar to the process and may, in the future, serve as a definite marker for dedifferentiation in their quest to comprehend the dedifferentiation process in a range of cell types and species.
Redifferentiation
Redifferentiation is the loss of differentiated cells’ recovered ability to divide. It enables differentiated cells in the plant body to behave as functionally specialised cells. The treated differentiated cells revert to the redifferentiated state, performing a specific function, after preparing the plant body for physiological or structural change by dedifferentiation. After cell division, the dedifferentiated vascular cambium, for example, redifferentiates into secondary xylem and phloem. The cells of the secondary xylem and secondary phloem, on the other hand, are incapable of further cell division, and after maturity, these cells execute activities such as food and water conduction while maintaining the structural integrity of the plant.
Similarities
Cells change their ability to divide through two mechanisms: dedifferentiation and redifferentiation. Both processes occur in differentiated cells. Both processes are also important in the genesis and healing of damage.
Differences
Definition – Dedifferentiation is the process by which structures or behaviours that were once specialised for a specific function lose their specialisation and become simplified or generalised, whereas redifferentiation is the process by which a group of previously differentiated cells returns to their original specialised form. The primary distinction between dedifferentiation and redifferentiation is therefore this.
Role – Furthermore, dedifferentiated tissue, such as interfascicular vascular cambium, cork cambium, and wound meristem, functions as meristematic tissue, whereas redifferentiated tissue functions as functionally-specialized tissue. As a result, another distinction between dedifferentiation and redifferentiation exists.
Importance – Another distinction between dedifferentiation and redifferentiation is that dedifferentiation permits the plant body to create new cells at a specific place, but redifferentiation is necessary for the plant to execute a certain function.
Examples – Dedifferentiation is the development of the interfascicular cambium and cork cambium from completely differentiated parenchyma cells, whereas redifferentiation is the specialisation of the vascular cambium into secondary xylem and phloem.
Learn more: Plant Growth and Development from Class 11 Biology