Sejtdifferenciáció

Sejtdifferenciáció is the process by which a less specialized cell becomes a more specialized cell type. This process occurs multiple times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types. Differentiation is a common process in adults as well, playing a role in tissue repair and the maintenance of certain cell populations.

The initial cells of an embryo are totipotent, meaning they can differentiate into all cell types, including extraembryonic tissues. As development progresses, cells become pluripotent, capable of differentiating into all cell types of the body but not extraembryonic tissues. Later still, cells become multipotent, able to differentiate into a limited range of cell types within a specific lineage. Finally, cells become unipotent, able to differentiate into only one cell type.

This specialization is driven by changes in gene expression. Although all cells in an organism contain the same genetic material, during differentiation, certain genes are activated or silenced, leading to the production of specific proteins that determine the cell's structure and function. These changes can be influenced by both internal signals (such as transcription factors) and external signals from neighboring cells or the environment.

The study of sejtdifferenciáció is crucial for understanding development, disease, and regenerative medicine. For example, the ability to direct the differentiation of stem cells holds promise for treating conditions like diabetes, Parkinson's disease, and spinal cord injuries by replacing damaged or lost cells.