CHAPTER 13 Summary

• Tissues are integrated groups of specialized cells that perform specific functions.
• Stem cells are relatively unspecialized cells that can divide and differentiate into different cell types.
• Adult stem cells, also known as somatic stem cells, are found in mature tissues; embryonic stem cells make up early embryos.
• Stem cells can be used therapeutically to engineer or regenerate tissues and organs.
• Making new tissues requires both cell division and cell differentiation. Cell differentiation is the process by which an unspecialized cell becomes a specialized cell with a unique function.
• All cells in the body have the same genome but express different genes. Such differential gene expression causes each cell type to produce different proteins and to have different functions.
• Adult stem cells are multipotent, capable of differentiating into a limited number of different cell types.
• Embryonic stem cells are pluripotent, capable of differentiating into nearly any cell type in the body.
• Embryonic stem cells can be obtained from human embryos or from cloned embryos. They may also be created by inducing adult cells to “de-differentiate.”
• In somatic cell nuclear transfer (SCNT), also known as cloning, the nucleus of an unfertilized egg is replaced by the nucleus of a donor cell to produce an embryo with the same genes as the donor cell.
• Both adult and embryonic stem cells are being investigated as possible therapies to restore damaged tissue in humans.

• MORE TO EXPLORE

  • Catalyst, ABC television (Oct, 2012): Organ Bioprinting http://www.abc.net.au/catalyst/stories/3618385.htm
  • Atala, A. (2011) TED Talk: Printing a human kidney http://www.ted.com/talks/anthony_atala_printing_a_human_kidney.html
  • Atala, A., et al. (2006) Tissue-engineered autologous bladders for patients needing cystoplasty. The Lancet 367:1241–46.
  • Raya-Rivera, A., et al. (2011) Tissue-engineered autologous urethras for patients who need reconstruction: an observational study. The Lancet 377:1175–82.
  • Junying, Y., et al. (2007) Induced pluripotent stem cell lines derived from human somatic cells. Science 318:1917–1920.