Structural inheritance

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Structural inheritance is the transmission of a 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 infections agents of diseases such as scrapie (in sheep and goats), bovine spongiform encephalopathy ('mad cow disease') and Cruetzfeld-Jakob disease (although the protein-only hypothesis of prion transmission has been considered contentious until recently.) [1] Prion-like propagating secondary structures also exist in yeast [2] ,[3]. Structural inheritance has also been seen in the orientation of cilia in protozoans such as Paramecium[4] and Tetrahymena, and 'handedness' of the sprial 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.

Various additional examples of structural inheritance are presented in the recent book Origination of Organismal Form.

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[edit] Notes and references

  1. ^ Soto C, Castilla J. The controversial protein-only hypothesis of prion propagation. Nat Med. 2004 Jul;10 Suppl:S63-7.
  2. ^ Tuite MF, Lindquist SL. Maintenance and inheritance of yeast prions. Trends Genet. 1996 Nov;12(11):467-71.
  3. ^ Serio TR, Cashikar AG, Kowal AS, Sawicki GJ, Lindquist SL. Self-perpetuating changes in Sup35 protein conformation as a mechanism of heredity in yeast. Biochem Soc Symp. 2001;(68):35-43.
  4. ^ BEISSON, J. & SONNEBORN, T. M. (1965). Cytoplasmic inheritance of the organization of the cell cortex of Paramecium aurelia. Proc. natn. Acad Sci. U.S.A. 53, 275-282
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