What is the Difference Between Cell Proliferation and Cell Differentiation

The main difference between cell proliferation and cell differentiation is that the cell proliferation is the process which increases the cell number whereas the cell differentiation is the process which alters the morphology and function of cells. 

Cell proliferation and cell differentiation are two processes that occur during the development of cells. While cell proliferation is a result of cell growth and cell division, cell differentiation is a result of the regulation of gene expression. 

Key Areas Covered 

1. What is Cell Proliferation
     – Definition, Mechanism, Importance
2. What is Cell Differentiation
     – Definition, Mechanism, Importance
3. What are the Similarities Between Cell Proliferation and Cell Differentiation
     – Outline of Common Features
4. What is the Difference Between Cell Proliferation and Cell Differentiation
     – Comparison of Key Differences

Key Terms 

Cell Differentiation, Cell Division, Cell Growth, Cell Potency, Cell Proliferation, Gene Expression Regulation 

What is Cell Proliferation 

Cell proliferation is the process responsible for the increase of cell number. The two stages of cell proliferation are cell growth and cell division. During the growth, cells synthesize new DNA and proteins required by cell division where the parent cells divide to produce daughter cells. The newly produced cells can either replenish a particular cell group or replace dead or damaged cells in tissues. Moreover, cell proliferation is balanced by apoptotic cell death and cell differentiation. 

Figure 1: The Cell Cycle

Most of the adult cells in animals enter the cell cycle in order to get proliferated. Some of these cells include smooth muscle cells, fibroblasts, epithelial cells of internal organs, and, endothelial cells. The main purpose of this proliferation is to replace the dead or damaged cells. On the other hand, adult stem cells are undifferentiated cells whose cell proliferation allows them to replenish the stem cell population and to replace dead and damaged cells. 

What is Cell Differentiation 

Cell differentiation is the process responsible for the functional specialization of cells in order to perform a particular target. Here, the differential regulation of gene expression results in the changes in the morphology and the function of the proliferated cells. However, the cell potency determines the degree of differentiation. The zygote that is the conceptus of fertilization is the diploid cell formed as a result of the fusion of male and female gametes. Also, it is totipotent, which means that the cells divided out from the zygote can differentiate into any type of cells in the body of the multicellular organism.  

Figure 2: Cell Differentiation

Moreover, the totipotent cells derived from the zygote further differentiate into pluripotent cells that are capable of differentiating into the cells of the three germ layers. In addition, the embryonic stem cells are the pluripotent cells which can differentiate into the cells of endoderm, mesoderm, and ectoderm. Furthermore, the cells in the corresponding germ layers differentiate into multipotent progenitor cells that can differentiate into discrete cell types.

These progenitor cells differentiate into oligopotent cells that are capable of differentiating into few types of cells. Here, hematopoietic stem cells in the bone marrow are a type of multipotent stem cells that can differentiate into any type of blood cells. However, myeloid and lymphoid progenitor cells differentiated from the hematopoietic stem cells are oligopotent stem cells. That means; the myeloid progenitor cells can only differentiate into red blood cells, mast cells, granulocytes, and platelets while the lymphoid progenitor cells differentiate into lymphocytes and natural killer cells. Also, the unipotent cells that occur in different tissues and organs can only differentiate into a specific type of cells in that tissue. For example, hepatoblasts in the liver can only differentiate into hepatocytes. 

Similarities Between Cell Proliferation and Cell Differentiation 

• Cell proliferation and cell differentiation are two processes which occur during the development of cells. 
• Both are important in replacing the dead or damaged cells in tissues of multicellular organisms. 

Difference Between Cell Proliferation and Cell Differentiation 

Definition 

Cell proliferation refers to the process which results in an increase of the number of cells and is defined by the balance between cell divisions and cell loss through cell death or differentiation. Cell differentiation refers to the process by which a less specialized cell becomes a more specialized cell type. Thus, this explains the main difference between cell proliferation and cell differentiation.

Significance 

The cell number increases due to cell proliferation while cells become functionally specialized due to cell differentiation. 

In Stem Cells 

Another difference between cell proliferation and cell differentiation is that the cell proliferation occurs first in stem cells while the proliferated cells then differentiate into functional cell types.  

Mechanism 

Moreover, cell proliferation occurs through cell growth and cell division while cell differentiation occurs through the regulation of gene expression.  

Importance 

While cell proliferation is important for both replenishing and replacing cells, cell differentiation is important for replacing the dead or damaged cells in a tissue. Hence, this is another difference between cell proliferation and cell differentiation.

Conclusion 

Cell proliferation is the process responsible for the increase of cell number. It occurs through cell growth and cell division. On the other hand, cell differentiation is the process responsible for the functional specialization of cells. It occurs through the regulation of gene expression. Both cell proliferation and cell differentiation are important in replacing the dead or damaged cells in tissues. Therefore, the main difference between cell proliferation and cell differentiation is the type of process.

References:

1. Cooper GM. The Cell: A Molecular Approach. 2nd edition. Sunderland (MA): Sinauer Associates; 2000. Cell Proliferation in Development and Differentiation. Available Here

Image Courtesy:

1. “Cell cycle with images” By WikiES – Own work (CC BY-SA 4.0) via Commons Wikimedia  
2. “422 Feature Stem Cell new” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia