Lesson plan

Structural inheritance

, an organelle involved in cell division, is structurally inherited. Structural inheritance or cortical inheritance is the transmission of an epigenetic trait in a living organism by a self-perpetuating spatial structures. This is in contrast to the transmission of digital information such as is found in DNA sequences, which accounts for the vast majority of known genetic variation. Examples of structural inheritance include the propagation of prions, the infectious proteins of diseases such as scrapie (in sheep and goats), bovine spongiform encephalopathy ('mad cow disease') and Creutzfeldt–Jakob disease (although the protein-only hypothesis of prion transmission has been considered contentious until recently). Prions based on heritable protein structure also exist in yeast. Structural inheritance has also been seen in the orientation of cilia in protozoans such as Paramecium and Tetrahymena, and 'handedness' of the spiral of the cell in Tetrahymena, and shells of snails. Some organelles also have structural inheritance, such as the centriole, and the cell itself (defined by the plasma membrane) may also be an example of structural inheritance. To emphasize the difference of the molecular mechanism of structural inheritance from the canonical Watson-Crick base pairing mechanism of transmission of genetic information, the term 'epigenetic templating' was introduced.

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Article summary

, an organelle involved in cell division, is structurally inherited. Structural inheritance or cortical inheritance is the transmission of an epigenetic trait in a living organism by a self-perpetuating spatial structures. This is in contrast to the transmission of digital information such as is found in DNA sequences, which accounts for the vast majority of known genetic variation. Examples of structural inheritance include the propagation of prions, the infectious proteins of diseases such as scrapie (in sheep and goats), bovine spongiform encephalopathy ('mad cow disease') and Creutzfeldt–Jakob disease (although the protein-only hypothesis of prion transmission has been considered contentious until recently). Prions based on heritable protein structure also exist in yeast. Structural inheritance has also been seen in the orientation of cilia in protozoans such as Paramecium and Tetrahymena, and 'handedness' of the spiral of the cell in Tetrahymena, and shells of snails. Some organelles also have structural inheritance, such as the centriole, and the cell itself (defined by the plasma membrane) may also be an example of structural inheritance. To emphasize the difference of the molecular mechanism of structural inheritance from the canonical Watson-Crick base pairing mechanism of transmission of genetic information, the term 'epigenetic templating' was introduced.

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Discussion questions

  1. Summarise the article in your own words. Which single claim would you verify first, and why?
  2. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
  3. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

Bibliography

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Key claims and bibliography are generated from the same tracked claims and sources as the article page.