The key difference between symmetric and asymmetric stem cell division is that symmetric stem cell division produces two differentiated cells or two stem cells with equal cell fates while asymmetric stem cell division produces one stem and one non-stem daughter cell, which have different fates.
Stem cells are undifferentiated cells that can proliferate indefinitely. They can differentiate into various cell types. Stem cells basically divide asymmetrically. However, they also show a symmetric division. When stem cells divide symmetrically, a mother stem cell produces two daughter cells with equal fates. In contrast, when a mother stem cell divides asymmetrically, it produces two cells with different fates.
CONTENTS
1. Overview and Key Difference
2. What is Symmetric Stem Cell Division
3. What is Asymmetric Stem Cell Division
4. Similarities Between Symmetric and Asymmetric Stem Cell Division
5. Side by Side Comparison – Symmetric vs Asymmetric Stem Cell Division in Tabular Form
6. Summary
What is Symmetric Stem Cell Division?
Symmetric stem cell division is one of the two types of cell divisions shown by stem cells. In symmetric stem cell division, mother stem cell produces two differentiated cells or two stem cells with equal fates. During symmetric cell division, cell fate-determining factors are evenly distributed to both daughter cells, resulting in equivalent cell fates. Moreover, spindle orientation and determinant protein localization are not coordinated in symmetric stem cell division.
Figure 01: Symmetric Stem Cell Division
The primary role of symmetric stem cell division is the proliferation. As a result, cell populations expand. Furthermore, symmetric stem cell division plays a key role in adult mammalian homeostasis. However, uncontrolled symmetric cell division is critical and is the major factor for causing cancers.
What is Asymmetric Stem Cell Division?
Asymmetric stem cell division is a central characteristic of stem cells. During the development of an organism, asymmetric stem cell division predominates. When a mother stem cell divides asymmetrically, it produces two qualitatively distinct daughter cells with different fates. Generally, one cell is a stem cell while the other cell is a differentiated cell. These two cells have different sizes, different morphology, and different gene expression patterns. The differentiated daughter cell goes along a specific cell lineage while the daughter stem cell renews its stem cell identity and continues to divide asymmetrically. This ability to produce two different cells with different fates is the reason for cellular diversity found in every multicellular organism.
Figure 02: Asymmetric Stem Cell Division
During asymmetric stem cell division, cell fate determinants segregate only into one of the two sister cells. Moreover, proteins and other cell-intrinsic factors, like mitochondria or mRNA, also distribute asymmetrically. Furthermore, during asymmetric stem cell division, spindle orientation and determinant protein localization are coordinated.
What are the Similarities Between Symmetric and Asymmetric Stem Cell Division?
- Symmetric and asymmetric cell divisions are two types of cell divisions shown by stem cells.
- Two daughter cells are produced in each cell division.
- Both types of cell divisions are important for multicellular organisms.
What is the Difference Between Symmetric and Asymmetric Stem Cell Division?
Symmetric stem cell division produces two differentiated cells or two stem cells from a mother stem cell. In contrast, asymmetric stem cell division produces one stem cell and one differentiated cell from a mother stem cell. The two daughter cells resulting from symmetric stem cell division have identical fates while two daughter cells resulting from asymmetric stem cell division have different fates. Thus, this is the key difference between symmetric and asymmetric stem cell division.
The below infographic lists more differences between symmetric and asymmetric stem cell division in tabular form.
Summary – Symmetric vs Asymmetric Stem Cell Division
Stem cells divide symmetrically or asymmetrically. Symmetric stem cell division produces two differentiated cells or two stem cells which have equal fates. Asymmetric stem cell division produces one differentiated cell and one stem cell which have different fates. So, this is the key difference between symmetric and asymmetric stem cell division. Moreover, asymmetric stem cell division predominates during the development phase of an organism. Importantly, uncontrolled symmetric stem cell division can cause cancers.
Reference:
1. Murke, Florian, et al. “Concise Review: Asymmetric Cell Divisions in Stem Cell Biology.” MDPI, Multidisciplinary Digital Publishing Institute, 5 Nov. 2015, Available here.
2. Yamashita, Yukiko M, et al. “Polarity in Stem Cell Division: Asymmetric Stem Cell Division in Tissue Homeostasis.” Cold Spring Harbor Perspectives in Biology, Cold Spring Harbor Laboratory Press, Jan. 2010, Available here.
Image Courtesy:
1. “Illustration of stem cell control by the niche” By Secker, G.A., and Daniels, J.T., Limbal epithelial stem cells of the cornea (June 30, 2009), StemBook, ed. The Stem Cell Research Community, StemBook, doi/10.3824/stembook.1.48.1 – (CC BY 3.0) via Commons Wikimedia
2. “Asymmetric cell division in Drosophila larval neuroblasts (NBs; on the left) and mammalian epithelia (on the right)” By Toledano, H. and Jones, D.L., Mechanisms regulating stem cell polarity and the specification of asymmetric divisions (March 31, 2009), StemBook, ed. The Stem Cell Research Community, StemBook, doi/10.3824/stembook.1.41.1 (CC BY 3.0) via Commons Wikimedia
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