Evolution of the Insertion-Deletion Mutation Rate Across the Tree of Life
Way Sung1,*, Matthew S. Ackerman2, Marcus M. Dillon3, Thomas G. Platt4, Clay Fuqua2, Vaughn S. Cooper5 and Michael Lynch2,**
- Author Affiliations
1 University of North Carolina at Charlotte;
2 Indiana University;
3 University of New Hampshire;
4 Indiana University; Kansas State University;
5 University of Pittsburgh School of Medicine
↵*To whom correspondence should be addressed. E-mail: waysung@indiana.edu
↵** Co-corresponding Author; E-mail: milynch@indiana.edu
Mutations are the ultimate source of variation used for evolutionary adaptation, while also being predominantly deleterious and a source of genetic disorders. Understanding the rate of insertiondeletion mutations (indels) is essential to understanding evolutionary processes, especially in coding regions where such mutations can disrupt production of essential proteins. Using direct estimates of insertion-deletion mutation rates from fourteen phylogenetically diverse eukaryotic and bacterial species, along with measures of standing variation in such species, we obtain results that imply an inverse relationship of the mutation rate and the effective population size. These results, which corroborate earlier observations on the base-substitution mutation rate, appear most compatible with the hypothesis that natural selection reduces mutation rates per effective genome to the point at which the power of random genetic drift (approximated by the inverse of effective population size) becomes overwhelming. Given that the substantial differences in the DNA metabolism pathways that give rise to these two types of mutations, this consistency of results raises the possibility that the refinement of other molecular and cellular traits may be inversely related to species-specific levels of random genetic drift.
drift barrier insertion-deletion mutation rate mutation accumulation mutation-rate evolution
Received May 8, 2016. Accepted June 13, 2016.
Copyright © 2016 Author et al.
This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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