Skin cell division is the process by which skin cells multiply to replace old or damaged cells, maintaining the integrity of the skin. It's a crucial process occurring continuously throughout life. Skin is one of the fastest dividing tissues in the body, with stem cells producing new cells every couple of days.[^1, ^2]
The Process
Cell division in the skin primarily happens in the stratum basale, the deepest layer of the epidermis.[^3] Basal cells, also known as young keratinocytes, undergo division. Each division results in two daughter cells. These daughter cells then either remain stem cells, continuing the cycle of division and renewal, or differentiate into specialized skin cells that migrate upwards through the epidermis, eventually shedding from the surface (desquamation).[^1, ^2, ^3]
Types of Skin Cell Division
Recent research has highlighted the fascinating flexibility of skin cell division:
- Standard Cell Division: This involves the typical cell cycle with DNA replication, resulting in two identical daughter cells. This is the primary mechanism for skin cell renewal.
- Asynthetic Fission: Studies, particularly in zebrafish, have shown that under certain conditions (like skin stretching), skin cells can divide without DNA replication. This process, called asynthetic fission, produces smaller daughter cells and is thought to be a more efficient method for expanding the skin surface quickly.[^4, ^8]
This flexibility suggests that skin cells can adapt their division strategies to meet specific needs, such as rapid wound healing or expansion during growth.
Importance of Skin Cell Division
Skin cell division is vital for several reasons:
- Skin Repair: It's essential for repairing wounds and injuries.
- Skin Renewal: It continuously replaces old, damaged, or dead cells, keeping the skin healthy and functioning properly.
- Maintaining the Skin Barrier: Proper cell division helps maintain the protective barrier of the skin against external factors like pathogens and environmental stressors.
[^1]: Researchers identify new way skin stops tumor growth | Fred Hutchinson Cancer Research Center. https://www.fredhutch.org/en/news/center-news/2018/10/beronja-oncogene-induced-differentiation-suppress-tumor.html
[^2]: Anatomy, Skin (Integument), Epidermis - StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK470464/
[^3]: Anatomy, Skin (Integument), Epidermis - StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK470464/
[^4]: Skin cells undergo asynthetic fission to expand body surfaces in ... https://www.nature.com/articles/s41586-022-04641-0
