Plastic Cells? How Different Are They?

Cellular plasticity refers to the ability of cells to differentiate into various cell types during development or in response to specific signals. The degree of plasticity varies among different types of cells. Here are the main states of cellular plasticity:

1. Totipotent Cells:
   • Definition: Totipotent cells have the highest degree of plasticity and can give rise to all cell types in an organism, including both embryonic and extraembryonic cells. These cells have the potential to form an entire organism.
   • Example: The zygote, formed by the fusion of a sperm and an egg during fertilization, is totipotent. In the early stages of development, the cells of the morula (a solid ball of cells) are also totipotent.
2. Pluripotent Cells:
   • Definition: Pluripotent cells have the capacity to differentiate into cells of all three germ layers—ectoderm, mesoderm, and endoderm. However, they cannot give rise to extraembryonic tissues like the placenta.
   • Example: Embryonic stem cells (ESCs) are pluripotent. These cells are derived from the inner cell mass of the blastocyst (an early-stage embryo) and can differentiate into a wide range of cell types.
3. Multipotent Cells:
   • Definition: Multipotent cells have a more limited differentiation potential compared to totipotent and pluripotent cells. They can differentiate into a specific range of cell types within a particular lineage or tissue.
   • Example: Adult or somatic stem cells are often multipotent. For instance, hematopoietic stem cells in the bone marrow can give rise to various blood cell types, but they cannot differentiate into non-hematopoietic cells.

As cells progress from totipotent to pluripotent to multipotent states during development, their differentiation potential becomes more restricted. This progression is associated with the specialization of cells into specific lineages and the development of various tissues and organs in the organism. It’s important to note that while totipotent and pluripotent cells are typically found in early embryonic stages, multipotent cells can be found throughout an organism’s life in various tissues to support tissue repair and regeneration.

Next Topic: HSCs (Hematopoietic Stem Cells) Are Multipotent

Source: ChatGPT response prompted and edited by Joel Graff.

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