Introduction

The stem cells are the cells that have the ability to self-renew and produce a daughter cell that can differentiate into other cell types.

Division and Self-Renewal

• A stem cell can divide symmetrically or asymmetrically.
  • If it divides symmetrically, it can produce two self-renewing stem cells or two daughter cells that are committed to differentiate.
  • If it divides asymmetrically, it can stabilize the stem cell pool and generate a daughter cell that will differentiate. This is called the single stem cell asymmetry mode.
• Another mode of this cell division is the population asymmetry mode, where some stem cells are more prone to produce differentiated cells, compensated by another set of stem cells that divide symmetrically.

Potency of a Stem Cell

Potency refers to the diversity of cell types that a stem cell can produce in vivo.

• Totipotent stem cell can produce all cell types of a lineage. In mammals, only the fertilized egg and the first 4 to 8 cells are totipotent.
• Pluripotent stem cell can produce all cells of the embryo.
• Multipotent stem cell have a restricted specificity for generating cell types within a tissue.
• Adult stem cells are multipotent but have limited self-renewal capacity, contributing to aging.
• When a multipotent stem cell divides asymmetrically, its daughter cell may transition as a progenitor cell, which can divide a few times before differentiating.
• Precursor cells refer to ancestral cell types of a lineage, which can be either stem cells or progenitor cells.
• Unipotent stem cell functions in the organism to generate only one cell type.

Summary

• A stem cell is a cell that can self-renew and differentiate into other cell types.
• Potency refers to the diversity of cell types that a stem cell can produce.
• Totipotent stem cell can produce all cell types of a lineage, while pluripotent stem cell can produce all cells of the embryo.
• Multipotent stem cell is restricted to generating cell types within a tissue, while adult stem cells have limited self-renewal capacity.
• Progenitor cells are daughter cells of a multipotent stem cell that can divide a few times before differentiating.
• Precursor cell referrs to ancestral cell types of a lineage, which can be either stem cell or progenitor cell.