sejtdifferenciálás

Sejtdifferenciálódás, or cell differentiation, is the process by which a less specialized cell becomes a more specialized cell type. This occurs multiple times during the development of a multicellular organism as the organism changes from a simple to a complex system. Differentiation is a common process in adults too, for example, the replacement of old cells or the repair of damaged tissues.

During cell differentiation, cells undergo changes in their gene expression, leading to distinct physical and biochemical properties. Initially, cells are totipotent, meaning they can differentiate into any type of cell, including extraembryonic tissues. As development progresses, cells become pluripotent, capable of differentiating into all cell types of the body, but not extraembryonic tissues. Later, they become multipotent, able to differentiate into a limited range of cell types. Finally, cells become unipotent, able to differentiate into only one cell type.

The process of differentiation is regulated by various internal and external signals, including hormones, growth factors, and cell-to-cell contact. These signals activate or repress specific genes, directing the cell's developmental pathway. Stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and therefore are used in regenerative medicine to repair damaged tissues or organs. Understanding sejtdifferenciálódás is crucial for fields like developmental biology, cancer research, and regenerative medicine.