8.2.1 Totipotent Cells

What are Totipotent Cells?

• Totipotent cells are a type of stem cell that can differentiate into:
  • Any cell type found in the body (e.g., muscle, nerve).
  • Extra-embryonic cells, such as those forming the placenta.
• Found in the early embryo (e.g., at the blastomere stage).
• Also referred to as embryonic stem cells.

Unspecialised to Specialised

• Initially unspecialised: Totipotent cells do not have specific functions when first formed.
• Differentiation: The process by which unspecialised cells become specialised to form specific tissues and organs.
• Differentiation occurs due to:
  • Selective gene expression:
  • Certain genes are switched on (expressed).
  • Others are switched off.
  • This selective switching determines the cell's function and type.