It is fascinating to know that division of labour exists among our body cells. That is why the cells in the eyes are different from the cells found in the brain and liver. Each of these cells performs a different task to foster the body’s effective functionality.
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Cell differentiation is the process by which living cells formed in the embryonic stage during the fetus development differentiates into many types in order to carry out different functions of the human body.
The precursor cells that differentiate into other cells in the body include:
- The stem cells
- The germ cells
The stem cells
Human body stem cells are of two types:
- Embryonic stem cells
- Adult stem cells
The embryonic stem cells are produced in the embryo during fetal development while the adult stem cells are found in three main parts of the human body: bone marrow, adipose tissues and blood. They are undifferentiated cells that have the ability to divide into different somatic cells in the living organisms and divide by mitosis
The germ cells
During embryonic development, germ cells are produced in the primitive streaks of the embryo and migrate through the gut of the embryo to the developing sex organs (gonads) where they are differentiated into either egg or sperm cells and divide by meiosis.
How body cells differentiate?
All living cells in the human body, both the ones in the brain, heart, intestine, lungs, liver and muscle carry the same genome (a complete set of the human genetic material). But these cells have distinctive shapes, sizes, and colours. The reason being that certain genes are repressed in some cells while certain genes are expressed through a process called gene expression.
Roles of gene expression regulation in cell differentiation
Soma cell
| Cells | Location | Insulin genes | Glutamate/Dopamine genes | Uromodulin genes | Melanin gene | Product/Protein | Function |
| B-cells | Liver | Expressed | Repressed | Repressed | Repressed | Insulin | Regulation of glucose level in the blood |
| Neurons | Nerve Tissues | Repressed | Expressed
|
Repressed | Repressed | Neurotransmitter | Signal transport protein |
| Podocytes | Kidney | Repressed | Repressed | Expressed
|
Repressed | Uromodulin | Found abundantly in urine, it may play a role in defence against urinary tract infections |
| Melanocytes | Skin | Repressed | Repressed | Repressed | Expressed
|
Melanin | It gives the skin its colour |
Germ cells
| Cells | Location | Genes in X-Chromosomes | Genes in Y-Chromosomes | Product | Function |
| Oocytes | Ovary | Expressed | Repressed | Fertilization | |
| Spermatocytes | Testes | Expressed | Expressed | Fertilization |