cellsundifferentiated

Undifferentiated cells are cells that have not yet acquired specialized characteristics or functions. In multicellular organisms, these cells are capable of giving rise to multiple cell types during development. They typically retain high proliferative capacity and the potential to differentiate along several lineages, a property known as potency.

Potency ranges from totipotent (able to form all embryonic and extraembryonic tissues) to pluripotent (able to form all body cell types but not extraembryonic tissues), to multipotent (able to form several related cell types), to unipotent (able to form one cell type). In early embryos, zygotes and early blastomeres are totipotent, while the inner cell mass of the blastocyst yields pluripotent embryonic stem cells. Adult stem cells are typically multipotent or more limited in lineage potential and are considered partly differentiated.

In cell culture, undifferentiated cells are maintained with defined signals and growth factors that preserve their state. They express core pluripotency transcription factors such as Oct4, Sox2, and Nanog in many systems. Induced pluripotent stem cells (iPSCs) are somatic cells reprogrammed to an undifferentiated, pluripotent state and can generate derivatives of all three germ layers.

Applications include basic developmental biology, disease modeling, drug screening, and regenerative medicine. Differentiation protocols guide these cells to specific lineages for potential replacement therapies. However, risks include unintended differentiation, genetic and epigenetic instability, and tumor formation from residual undifferentiated cells, particularly with pluripotent lines. Ethical and regulatory considerations also apply to the use of some undifferentiated cell types, especially embryonic sources.

See also embryonic stem cells, induced pluripotent stem cells, stem cell potency, teratoma assay.