Definition: Ability of a particular stem cell to generate various differentiated cell types.
Stem cells have ability of self renewal.
1) Totipotent Stem Cells:
- Capable of forming every cell in the embryo.
- Also, capable of forming trophoblast cells of placenta.
- Example: Zygote & first 4-8 blastomeres.
2) Pluripotent Stem Cells:
- Capable of forming all cell types of embryo.
- NOT capable of forming trophoblast.
- Capable of producing all three germ layer cells, also, of producing germ cells.
- Example: Cells derived from inner cell mass of mammalian blastocyst.
- Germ cells & germ cell tumors can also form pluripotent stem cells.
3) Multipotent Stem Cells:
- Capable of forming relatively small subset of all possible body cells.
- Usually adult stem cells.
- Example: Hematopoietic stem cells – forms granulocyte, platelet & RBC lineages; Mammary stem cells – forms mammary gland cell types.
4) Unipotent Stem Cells:
- Capable of generating a particular cell type.
- Example: Spermatogonia – give rise to only sperms.
|S.No.||Terminology||Type of Cells|
|1||Committed Stem Cells||a) Multipotent stem cells |
b) Unipotent stem cells
(Since, they have potential to become relatively few cell types.)
|2||Lineage Restricted Cells||a) Unipotent stem cells |
b) Progenitor cells
- Capable of dividing only a few times before differentiating.
- NOT capable of self renewal.
- Also called, Transit-Amplifying Cells (Since, they usually divide while migrating away from stem cell niche).
- Usually more differentiated than stem cells.
- Have become committed for becoming a particular cell type.