Stem Cell Concepts

 

Two main characteristics define stem cells: the ability to divide multiple times without differentiating (Self-Renewal) and the capacity to differentiate into specialized cell types (Potency). These terms are discussed below.

Obligatory Asymmetric Replication: the cell divides, maintaining the stem cell population with one copy and one differentiated daughter cell.


 

Stochastic Differentiation: one father stem cell divides into two differentiated daughter cells. In order to maintain the population, a second father cell divides into two stem cells.


 

Totipotency: totipotent cells are obtained from a joined sperm and egg cell, it can differentiate into embryonic and extraembryonic cells. It has the capacity to create a completely viable organism.

 

Pluripotency: pluripotent cells are derived from totipotent cellsand have the potential to differentiate into almost any cell (i.e., embryonic stem cells from blastocyst).

 

 

Embryonic Stem Cell

 

Multipotency: cells that can give rise to multiple cell types. These cells are typically closely related For example, Hematopoietic Stem Cell can change into several types of blood cells, but not brain cells.

 

 

Hematopoietic Stem Cell

 

Oligopotency: the cell can only differentiate into a few cell types (i.e., myeloid or lymphoid progenitor cells).

 

 

Common Lymphoid Progenitor

 

Unipotency:  it can only make one cell type: itself. It also has the power to self-renew (i.e., hepatocytes).

 

 

Hepatocytes

 

References:

  1. Appelbaum, F.R. et al. 2009. Thomas’ Hematopoietic Cell Transplantation. 4th ed. John Wiley & Sons.
  2. Dingli, D. et al. 2007. PLoS Comput. Biol. 3: e53.
  3. Lander, A.D. 2009. J. Biol. 8:70.
  4. Mitalipov, S., and Wolf, D. 2009. Adv. Biochem. Eng. Biotechnol. 114:185.