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Mutagenesis Mechanisms

  1. Yaroslava Y Polosina,
  2. Claire G Cupples

Published Online: 15 FEB 2011

DOI: 10.1002/9780470015902.a0000837.pub2



How to Cite

Polosina, Y. Y. and Cupples, C. G. 2011. Mutagenesis Mechanisms. eLS. .

Author Information

  1. Simon Fraser University, Department of Molecular Biology and Biochemistry, Burnaby, British Columbia, Canada

Publication History

  1. Published Online: 15 FEB 2011


Deoxyribonucleic acid (DNA), the keeper of genetic information in all organisms, is constantly modified by internal and external factors during the cell's lifetime. Many types of DNA modification cause mutations. Although mutations may be harmful to individual cells or organisms, mutation in populations is valuable because it leads to genetic variation and ultimately to evolution. There are even circumstances when it is useful to increase the number of mutations in a cell. Maintaining the optimum balance between genetic stability and variability requires the cell to regulate both the frequency with which modifications to the DNA occur, and the efficiency with which the original sequence is restored by the various DNA repair pathways. One group of cellular enzymes, the DNA polymerases, plays a key role in both mutation occurrence and mutation avoidance. In this article we consider how mutations occur in DNA, and how cells regulate their mutation rate, with an emphasis on the role of the DNA polymerases.

Key Concepts:

  • Modification of DNA structure is the first step in the pathway to mutation.

  • Most structural changes in DNA are caused by normal physiological processes.

  • Mutation frequency depends on the frequency of DNA structural change and the efficiency of DNA repair processes.

  • DNA polymerase is the key enzyme of mutagenesis.

  • Mutations are a cause of genetic disease.

  • Mutations are the raw material for evolution.

  • To ensure survival, cells must maintain the optimal balance between genetic stability and variability.


  • mutagenesis;
  • frameshift;
  • base substitution;
  • transition;
  • transversion;
  • DNA polymerase;
  • DNA repair;
  • missense mutation;
  • nonsense mutation;
  • error catastrophe