Mutation Rate of Non-CpG DNA
Published Online: 15 DEC 2009
Copyright © 2001 John Wiley & Sons, Ltd. All rights reserved.
How to Cite
Furano, A. V. and Walser, J.-C. 2009. Mutation Rate of Non-CpG DNA. eLS. .
- Published Online: 15 DEC 2009
Base substitutions (mutations) change the informational content of deoxyribonucleic acid (DNA). Therefore, understanding the determinants of the base mutation rate is a fundamental problem in biology. Biochemically, mutations are a function of the fidelity of DNA replication, damage and repair. Each can be affected by nucleotide composition and context. However, various downstream factors determine the ultimate survival of these mutations in a population, including natural selection and chance (genetic drift). The result in mammals is two dramatically different mutation rates. The C of most CpG dinucleotides mutates approximately 10- to 50-fold faster than Cs in other contexts or any other nucleotide (i.e. in non-CpG sites). But, the non-CpG mutation rate also varies between different genomic regions. Here we address the difference between CpG and non-CpG mutation rates and the factors that are correlated with the variance in non-CpG rates. A predominant one is CpG content.
Evolutionary processes determine the extent to which the base substitutions (mutations), which result from biochemical errors inherent in the processes that replicate and maintain the integrity of the genome, contribute to the mutation rate experienced by a population.
These biochemical mutations are a function of the fidelity of DNA replication, the efficiency with which replication errors and DNA damage are repaired and whether DNA repair processes themselves produce errors in undamaged DNA.