2.4 cell differentiation

• Cell differentiation is the process where cells, tissues and organs acquire special features.
• stem cells that don’t differentiate
• Totipotent stem cells:

  • Give rise to all different cell types
• Pluripotent stem cells:

  • Cells of primary germ layers
  • Endoderm: innermost primary germ layer that differentiates into digestive lining and organs
  • Mesoderm: middle primary germ layer that differentiates into many different organs
  • Ectoderm: most external germ or cell layer which differentiates into epithelial tissue, covering the outer surfaces of the body
• Multipotent stem cells:

  • Can differentiate into a number of closely related cell types
• Oligopotent stem cells:

  • Have the ability to differentiate into a few different cell types
• Unipotent stem cells:

  • Can produce only cells of their own type
  • Termed stem cells because they can self-renew
  • Examples include adult (somatic) muscle stem cells
• embryos have to be destroyed to get embryonic stem cells
• Zygote - fertilized egg
• Embryonic stem cells (ESCs) an undifferentiated cell obtained from early embryonic tissue that is capable of differentiating into many cell types
• Parthenotes potential source of embryonic stem cells, derived from unfertilised human eggs that are artificially stimulated to begin development
• Adult stem cells undifferentiated cells obtained from various sources and capable of differentiating into related cell types; also known as somatic stem cells
• Induced pluripotent stem cells (iPSCs) a stem cell that has been genetically reprogrammed to return to an undifferentiated embryonic state
• Stem cell myeloid:

  red blood cells

  platelets

  basophils

  eosinophil

  neutrophil

  Monocyte->macrophage
• stem cell lymphoid:

  B lymphocyte

  T lymphocyte
• Totipotent- can differentiate to all cells
• pluripotent: can differentiate to many cell types
• multipotent: can differentiate to closely related cells
• oligopotnet: can differentiate into a few cell types
• unipotent: can only differentiate to its own type.