- Structural inheritance
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 inDNA sequences, which accounts for the vast majority of known genetic variation.Examples of structural inheritance include the propagation of
prion s, 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.) [ Soto C, Castilla J. The controversial protein-only hypothesis of prion propagation. Nat Med. 2004 Jul;10 Suppl:S63-7. ] Prion-like propagating secondary structures also exist inyeast [Tuite MF, Lindquist SL. Maintenance and inheritance of yeast prions. Trends Genet. 1996 Nov;12(11):467-71.] , [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.] . Structural inheritance has also been seen in the orientation of cilia in protozoans such as "Paramecium" [ 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 ] and [http://dev.biologists.org/cgi/reprint/105/3/447 "Tetrahymena"] , and 'handedness' of the sprial of the cell in [http://dev.biologists.org/cgi/reprint/105/3/447 "Tetrahymena"] , and shells of snails. Someorganelle s also have structural inheritance, such as the centriole, and the cell itself (defined by theplasma 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 .External links
*"
Proceedings of the National Academy of Sciences " supplement: [http://www.pnas.org/content/vol99/suppl_4/ "Self-Perpetuating Structural States in Biology, Disease, and Genetics"]Notes and references
Wikimedia Foundation. 2010.
