Final answer:
Stem cells specialize into different types of cells through the process of differentiation, where transcription factors determine which genes are turned on or off. This selective gene expression gives cells their unique characteristics and functions. Once specialized, the stable expression of these gene patterns maintains the cell's specialization.
Step-by-step explanation:
Cellular Specialization and Differentiation
A stem cell is initially an unspecialized cell with the potential to divide indefinitely and differentiate into various types of specialized cells. The process of a cell becoming specialized is known as differentiation. This journey from a generalized, undifferentiated cell to a specialized one is dictated by the selective expression of the cell's genes.
Although all somatic cells possess the same genome, specialization occurs because only certain genes are expressed at any given time in a cell. This selective gene expression is heavily influenced by transcription factors, proteins that bind to DNA and influence the transcription of specific genes. As these transcription factors regulate gene expression, cells take on unique structural and functional characteristics, defining their specialization.
Understanding how a cell maintains its specialization involves studying the persistence of gene expression patterns and the role of the cell environment in influencing these patterns. Specialized cells generally maintain their identity through cell divisions due to the stable expression of specific sets of genes required for their specialized functions.