What is the Difference Between Stem Cells and Specialised Cells

The main difference between stem cells and specialised cells is that stem cells are the undifferentiated cells of a multicellular organism whereas specialized cells are the differentiated cells to perform a unique function in the body. 

Stem cells and specialized cells are two types of cells in the body of a multicellular organism. While stem cells are capable of self-renewing and differentiating into specialized cells, most specialized cells cannot proliferate.

Key Areas Covered

1. What are Stem Cells
     – Definition, Types, Importance
2. What are Specialised Cells
     – Definition, Characteristics, Importance
3. What are the Similarities Between Stem Cells and Specialised Cells
     – Outline of Common Features
4. What is the Difference Between Stem Cells and Specialised Cells
     – Comparison of Key Differences                

Key Terms

Differentiation, Potency, Proliferation, Regulation of Gene Expression, Specialised Cells, Stem Cells

What are Stem Cells

Stem cells are the undifferentiated cells found in the body of multicellular organisms. The two main characteristic features of stem cells are the ability to self-renewal and the ability to differentiate into specialised cells. Therefore, stem cells are responsible for replenishing old, injured or dead cells from the body. The main importance of stem cells is that they can be isolated and used for therapeutic and research purposes.

Figure 1: Cell Differentiation

The three main types of stem cells are embryonic stem cells, fetal stem cells, and adult stem cells.

Embryonic stem cells – the stem cells in the inner cell mass of the embryo derived from the totipotent cells of the zygote. They are pluripotent cells that give rise to the three germ layers.

Fetal stem cells – the primitive stem cells in the fetus.

Adult stem cells – the stem cells in different organs of adults. Some adult stem cells including hematopoietic stem cells are multipotent, giving rise to several types of functionally-related cells while the others such as neuron stem cells are unipotent, giving rise to a single type of specialized cells found in a particular tissue or organ.

What are Specialised Cells

Specialised cells are the differentiated cells in the body, performing a unique function. They have a unique morphology, metabolic activity, membrane potentials, and responsiveness to signals. Differential regulation of gene expression is responsible for the formation of specialised cells. That means; each type of specialized cell consists of a unique array of transcription factors, which regulate the expression of a specific set of genes while keeping other genes silent.

Figure 2: Specialised Blood Cells

Most specialised cells cannot proliferate and they rest in their G₀ phase of the cell cycle. Nevertheless, as a result of cell injury, these cells can enter into the cell cycle and undergo cell division. Epithelial cells, skin fibroblasts, endothelial cells lining the blood vessels and smooth muscle cells are some examples of specialised cells that can gain the ability of proliferation upon injury. In contrast, some specialised cells such as cardiac muscle cells are incapable of proliferating. Moreover, some specialised cells rarely undergo proliferation such as nerve cells in the brain and liver cells.

Similarities Between Stem Cells and Specialised Cells

• Stem cells and specialized cells are two types of cell in the body of multicellular organisms.
• They perform important functions in the body.

Difference Between Stem Cells and Specialised Cells

Definition

Stem cells refer to the undifferentiated cells of a multicellular organism capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation while specialised cells refer to the cells in multicellular organisms modified to carry out a particular function, such as transporting a certain substance or executing a specific task. Thus, this is the main difference between stem cells and specialised cells.

Proliferation

Also, another difference between stem cells and specialised cells is that the stem cells can proliferate to produce new cells while most specialised cells are unable to proliferate.

Degree of Differentiation

A major difference between stem cells and specialised cells is that the stem cells are undifferentiated cells while specialised cells are differentiated cells.

Morphology

Moreover, the stem cells are mainly round in shape and small while specialised cells have a unique shape. Hence, this is also a difference between stem cells and specialised cells.

Occurrence

Furthermore, one other difference between stem cells and specialised cells is their location. Stem cells occur in the embryo, fetus, and most organs of the body while specialised cells occur in distinct locations of the body.

Function

Besides, an important difference between stem cells and specialised cells is their function. The main function of stem cells is to replenish old, injured or dead cells while different types of specialised cells perform distinct functions in the body.

Examples

Cells in bone marrow, brain, blood, liver, skin, dental pulp, the eye, skeletal muscle, pancreas and gastrointestinal tract are examples of stem cells while epithelial cells, skin fibroblasts, endothelial cells lining the blood vessels, smooth muscle cells, liver cells, nerve cells, and human cardiac muscle cells are examples of specialised cells.

Conclusion

Stem cells are undifferentiated cells capable of self-renewing and differentiating into various types of differentiated cells of the body. Therefore, their main function is to replenish the old, injured or dead cells of the body. In comparison, specialised cells are the differentiated cells that perform a unique function in the body. Thus, the main difference between stem cells and specialised cells is the role of the cells in the body.

References:

1. “Stem Cell Basics II.” National Institutes of Health, U.S. Department of Health and Human Services, Available Here.
2. “What Are Specialised Cells? – BBC Bitesize.” BBC News, BBC, 20 Dec. 2018, Available Here.

Image Courtesy:

1. “422 Feature Stem Cell new” By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia  
2. “Figure 40 02 03ab” By CNX OpenStax (CC BY 4.0) via Commons Wikimedia