Silent mutation

Point substitution mutations of a codon, classified by their impact on protein sequence

Silent mutations, also called synonymous or samesense mutations, are mutations in DNA that do not have an observable effect on the organism's phenotype. The phrase silent mutation is often used interchangeably with the phrase synonymous mutation; however, synonymous mutations are not always silent, nor vice versa.[1][2][3][4][5] Synonymous mutations can affect transcription, splicing, mRNA transport, and translation, any of which could alter phenotype, rendering the synonymous mutation non-silent.[3] The substrate specificity of the tRNA to the rare codon can affect the timing of translation, and in turn the co-translational folding of the protein.[1] This is reflected in the codon usage bias that is observed in many species. Mutations that cause the altered codon to produce an amino acid with similar functionality (e.g. a mutation producing leucine instead of isoleucine) are often classified as silent; if the properties of the amino acid are conserved, this mutation does not usually significantly affect protein function.[6]

  1. ^ a b Kimchi-Sarfaty C, Oh JM, Kim IW, Sauna ZE, Calcagno AM, Ambudkar SV, Gottesman MM (January 2007). "A "silent" polymorphism in the MDR1 gene changes substrate specificity". Science. 315 (5811): 525–8. Bibcode:2007Sci...315..525K. doi:10.1126/science.1135308. PMID 17185560. S2CID 15146955.
  2. ^ Chamary JV, Parmley JL, Hurst LD (February 2006). "Hearing silence: non-neutral evolution at synonymous sites in mammals". Nature Reviews. Genetics. 7 (2): 98–108. doi:10.1038/nrg1770. PMID 16418745. S2CID 25713689.
  3. ^ a b Goymer P (February 2007). "Synonymous mutations break their silence". Nature Reviews Genetics. 8 (2): 92. doi:10.1038/nrg2056. S2CID 29882152.
  4. ^ Zhou T, Ko EA, Gu W, Lim I, Bang H, Ko JH (31 October 2012). "Non-silent story on synonymous sites in voltage-gated ion channel genes". PLOS ONE. 7 (10): e48541. Bibcode:2012PLoSO...748541Z. doi:10.1371/journal.pone.0048541. PMC 3485311. PMID 23119053.
  5. ^ Graur D (2003). "Single Base Mutation" (PDF). In Cooper DN (ed.). Nature Encyclopedia of the Human Genome. MacMillan. ISBN 978-0333803868.
  6. ^ Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2007). Molecular Biology of the Cell. Garland Science. p. 264. ISBN 978-1-136-84442-3.