multipotent

Meaning: A multipotent cell is a stem cell that can become a limited set of cell types, generally those of one tissue or lineage. The standard example is the hematopoietic stem cell in bone marrow, which gives rise to red blood cells, platelets and white blood cells (myeloid and lymphoid lines). Potency narrows as development proceeds: totipotent (zygote and earliest embryonic cells; can form the embryo and placenta), pluripotent (embryonic stem cells; all three germ layers), multipotent, then unipotent (one cell type). The narrowing reflects changes in gene expression, not loss of DNA.

On the MCAT: Expect questions that ask you to rank cells by potency or classify a cell described in a passage, such as an adult stem cell used in a bone marrow transplant. Induced pluripotent stem cells, made by reprogramming somatic cells with transcription factors, may appear as a contrast. Under normal conditions, a multipotent cell does not give rise to cells outside its lineage.

Common confusion: Students swap pluripotent and multipotent. Pluripotent cells can form cells of all three germ layers; multipotent cells are restricted to a related family of cell types. Multipotent is also not unipotent, because it still has more than one possible fate.